Securities - Securities with Unrealized Losses at Year End - Securities Available-for-sale (Details) $ in Thousands	Dec. 31, 2015 USD ($)
Available-for-sale, Fair Value
Less Than 12 Months	$ 276,050
12 Months or More	2,165
Total	278,215
Available-for-sale, Unrealized Losses
Less Than 12 Months	(2,316)
12 Months or More	(46)
Total	(2,362)
Agency mortgage-backed securities
Available-for-sale, Fair Value
Less Than 12 Months	241,067
12 Months or More	2,165
Total	243,232
Available-for-sale, Unrealized Losses
Less Than 12 Months	(2,258)
12 Months or More	(46)
Total	(2,304)
U.S. Treasury
Available-for-sale, Fair Value
Less Than 12 Months	30,003
Total	30,003
Available-for-sale, Unrealized Losses
Less Than 12 Months	(44)
Total	(44)
U.S. Government sponsored entities
Available-for-sale, Fair Value
Less Than 12 Months	4,980
Total	4,980
Available-for-sale, Unrealized Losses
Less Than 12 Months	(14)
Total	$ (14)