v3.7.0.1
Investment Securities Continuous Unrealized Loss (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]      
Fair value, less than 12 months $ 67,857   $ 80,425
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate loss accumulated in investments (406)   (442)
Fair value, 12 months or more 67,129   64,319
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate loss, accumulated in investments (472)   (536)
Total fair value 134,986   144,744
Available-for-sale securities, continuous unrealized loss position,aggregate loss, accumulated in investments (878)   (978)
Other than temporary impairment losses 0 $ 0  
Corporate bonds [Member]      
Schedule of Available-for-sale Securities [Line Items]      
Fair value, less than 12 months 2,221   8,739
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate loss accumulated in investments (3)   (7)
Fair value, 12 months or more 3,999   1,999
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate loss, accumulated in investments (3)   0
Total fair value 6,220   10,738
Available-for-sale securities, continuous unrealized loss position,aggregate loss, accumulated in investments (6)   (7)
Commercial paper [Member]      
Schedule of Available-for-sale Securities [Line Items]      
Fair value, less than 12 months     2,672
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate loss accumulated in investments     (1)
Fair value, 12 months or more     0
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate loss, accumulated in investments     0
Total fair value     2,672
Available-for-sale securities, continuous unrealized loss position,aggregate loss, accumulated in investments     (1)
US treasury notes [Member]      
Schedule of Available-for-sale Securities [Line Items]      
Fair value, less than 12 months 21,132   16,211
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate loss accumulated in investments (52)   (41)
Fair value, 12 months or more 0   0
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate loss, accumulated in investments 0   0
Total fair value 21,132   16,211
Available-for-sale securities, continuous unrealized loss position,aggregate loss, accumulated in investments (52)   (41)
Agencies securities [Member]      
Schedule of Available-for-sale Securities [Line Items]      
Fair value, less than 12 months     4,002
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate loss accumulated in investments     (1)
Fair value, 12 months or more     0
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate loss, accumulated in investments     0
Total fair value     4,002
Available-for-sale securities, continuous unrealized loss position,aggregate loss, accumulated in investments     (1)
Mortgage-backed securities [Member]      
Schedule of Available-for-sale Securities [Line Items]      
Fair value, less than 12 months 19,346   23,300
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate loss accumulated in investments (213)   (236)
Fair value, 12 months or more 62,309   61,383
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate loss, accumulated in investments (452)   (505)
Total fair value 81,655   84,683
Available-for-sale securities, continuous unrealized loss position,aggregate loss, accumulated in investments (665)   (741)
Municipal bonds [Member]      
Schedule of Available-for-sale Securities [Line Items]      
Fair value, less than 12 months 0   0
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate loss accumulated in investments 0   0
Fair value, 12 months or more 821   937
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate loss, accumulated in investments (17)   (31)
Total fair value 821   937
Available-for-sale securities, continuous unrealized loss position,aggregate loss, accumulated in investments (17)   (31)
Asset-backed securities [Member]      
Schedule of Available-for-sale Securities [Line Items]      
Fair value, less than 12 months 25,158   25,501
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate loss accumulated in investments (138)   (156)
Fair value, 12 months or more 0   0
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate loss, accumulated in investments 0   0
Total fair value 25,158   25,501
Available-for-sale securities, continuous unrealized loss position,aggregate loss, accumulated in investments $ (138)   $ (156)