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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Period of maturity of a debt security categorized as neither trading nor held-to-maturity, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Fair value portion of cash and investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Fair Value Measurement, Adjusted Cost, Gross Unrealized Gains, Gross Unrealized Losses and Fair Value by Investment Category (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Adjusted Cost	$ 6,627	$ 8,726	$ 18,658	$ 19,173
Adjusted Cost	12,445	15,390
Unrealized Gains	2	1
Unrealized Losses	(3)	(7)
Fair Value	12,444	15,384
Adjusted Cost	15,877	18,686
Fair Value	15,876	18,680
Investments Available for Sale	$ 12,444	15,384
Minimum [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Maturities of available for sale securities	1 year
Maximum [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Maturities of available for sale securities	2 years
Cash [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Adjusted Cost	$ 3,432	3,296
Fair Value	3,432	3,296
Cash and Cash Equivalents	3,432	3,296
Mutual Funds [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Adjusted Cost	3,195	5,005
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	3,195	5,005
Investments Available for Sale	3,195	5,005
U.S. Government Securities [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Adjusted Cost	1,254	1,806
Unrealized Gains	0	0
Unrealized Losses	0	(3)
Fair Value	1,254	1,803
Investments Available for Sale	1,254	1,803
US Agency Securities [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Adjusted Cost	7,996	8,579
Unrealized Gains	2	1
Unrealized Losses	(3)	(4)
Fair Value	7,995	8,576
Investments Available for Sale	7,995	8,576
Recurring [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Fair Value	6,627	8,726
Fair Value	9,249	9,954
Cash and Cash Equivalents	6,627	8,726
Investments Available for Sale	9,249	9,954
Recurring [Member] \| Cash [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Fair Value	3,432	3,296
Cash and Cash Equivalents	3,432	3,296
Recurring [Member] \| Level 1 [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Fair Value	3,195	5,430
Fair Value	9,249	9,954
Cash and Cash Equivalents	3,195	5,430
Investments Available for Sale	9,249	9,954
Recurring [Member] \| Level 1 [Member] \| Mutual Funds [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Fair Value	3,195	5,005
Fair Value	0	0
Cash and Cash Equivalents	3,195	5,005
Investments Available for Sale	0	0
Recurring [Member] \| Level 1 [Member] \| U.S. Government Securities [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Fair Value	0	0
Fair Value	1,254	1,803
Cash and Cash Equivalents	0	0
Investments Available for Sale	1,254	1,803
Recurring [Member] \| Level 1 [Member] \| US Agency Securities [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Fair Value	0	425
Fair Value	7,995	8,151
Cash and Cash Equivalents	0	425
Investments Available for Sale	$ 7,995	$ 8,151