Fair Value Measurements (Details 3)
$ in Thousands
3 Months Ended
Mar. 31, 2016
USD ($)
item
Mar. 31, 2015
USD ($)
item
Changes in the fair value of Level 3 assets measured on a recurring basis    
Total gains or losses (unrealized): included in earnings $ 0 $ 0
Number of transfers between levels | item 0 0
U.S. States and political subdivisions securities    
Changes in the fair value of Level 3 assets measured on a recurring basis    
Balance at the beginning of the period $ 4,528 $ 6,466
Total gains or losses (realized/unrealized): included in earnings 0 0
Total gains or losses (realized/unrealized): included in other comprehensive income 35 (7)
Purchases 1,100 0
Issuances 0 0
Sales 0 0
Settlements 0 0
Maturities (853) (827)
Transfers into Level 3 0 0
Transfers out of Level 3 0 0
Balance at the end of the period 4,810 5,632
Foreign government and other securities    
Changes in the fair value of Level 3 assets measured on a recurring basis    
Balance at the beginning of the period 809 811
Total gains or losses (realized/unrealized): included in earnings 0 0
Total gains or losses (realized/unrealized): included in other comprehensive income 0 (3)
Purchases 0 0
Issuances 0 0
Sales 0 0
Settlements 0 0
Maturities 0 0
Transfers into Level 3 0 0
Transfers out of Level 3 0 0
Balance at the end of the period 809 808
Investment securities available-for-sale    
Changes in the fair value of Level 3 assets measured on a recurring basis    
Balance at the beginning of the period 5,337 7,277
Total gains or losses (realized/unrealized): included in earnings 0 0
Total gains or losses (realized/unrealized): included in other comprehensive income 35 (10)
Purchases 1,100 0
Issuances 0 0
Sales 0 0
Settlements 0 0
Maturities (853) (827)
Transfers into Level 3 0 0
Transfers out of Level 3 0 0
Balance at the end of the period $ 5,619 $ 6,440