Fair Value (Fair Value, Assets Measured on Recurring Basis Using Significant Unobservable Inputs (Level 3)) (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Fair Value [Abstract]    
Beginning balance as of January 1 $ 14,598 $ 17,517
Sales $ (370) $ (3,490)
Settlements
Purchases
Issuances
Total realized/unrealized gains included in net income
Net gains included in other comprehensive income $ (141) $ 571
Transfers into Level 3
Transfers out of Level 3
Ending balance as of December 31 $ 14,087 $ 14,598