Other Comprehensive Income (Loss) - Summary of reclassifications out of accumulated other comprehensive income (loss) (Details 1) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Unrealized gains and losses on available-for-sale securities, Total before tax	$ 5,831	$ (7,729)	$ 13,959	$ (3,466)
Amount reclassified from Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Unrealized gains and losses on available-for-sale securities, Total before tax	133	(897)	369	(840)
Unrealized gains and losses on available-for-sale securities, Tax benefit (expense)	(44)	291	(120)	271
Unrealized gains and losses on available-for-sale securities, Net of tax	$ 89	$ (606)	$ 249	$ (569)