v3.7.0.1
Investment Securities Gross Gains and Losses (Details) - USD ($)
$ in Thousands
Mar. 31, 2017
Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]    
Amortized cost basis $ 184,475 $ 209,146
Gross unrealized gains 212 258
Gross unrealized losses (878) (978)
Fair value 183,809 208,426
Corporate bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized cost basis 12,060 21,533
Gross unrealized gains 5 9
Gross unrealized losses (6) (7)
Fair value 12,059 21,535
Commercial paper [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized cost basis 3,885 12,427
Gross unrealized gains 0 4
Gross unrealized losses 0 (1)
Fair value 3,885 12,430
US treasury notes [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized cost basis 25,888 21,603
Gross unrealized gains 1 1
Gross unrealized losses (52) (41)
Fair value 25,837 21,563
Agencies securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized cost basis   4,002
Gross unrealized gains   0
Gross unrealized losses   (1)
Fair value   4,001
Mortgage-backed securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized cost basis 112,838 117,990
Gross unrealized gains 204 242
Gross unrealized losses (665) (741)
Fair value 112,377 117,491
Municipal bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized cost basis 1,304 1,460
Gross unrealized gains 1 1
Gross unrealized losses (17) (31)
Fair value 1,288 1,430
Asset-backed securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized cost basis 28,500 30,131
Gross unrealized gains 1 1
Gross unrealized losses (138) (156)
Fair value $ 28,363 $ 29,976