Accumulated Other Comprehensive Income (Loss) - Summary of Reclassification out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Unrealized gains on debt securities:
Unrealized gains on available-for-sale investments before-tax amount	$ 3,257	$ 3,710	$ 3,259	$ 6,956
Unrealized gains on available-for-sale investments tax benefit or (expense)	(1,253)	(1,465)	(1,254)	(2,738)
Unrealized gains on available-for-sale investments net-of-tax amount	2,004	2,245	2,005	4,218
Reclassification of realized gains included in earnings	(40)	(5,276)	(40)	(5,276)
Less: reclassification adjustment for gains included in earnings tax benefit or (expense)	15	2,522	15	2,522
Less: reclassification adjustment for gains included in earnings net-of-tax	(25)	(2,754)	(25)	(2,754)
Total before income taxes	3,217	(1,566)	3,219	1,680
Net unrealized gains tax benefit or (expense)	(1,238)	1,057	(1,239)	(216)
Net unrealized gains net-of-tax amount	(1,979)	509	(1,980)	(1,464)
Other comprehensive income (loss) before-tax amount	3,217	(1,566)	3,219	1,680
Other comprehensive income (loss) tax benefit or (expense)	(1,238)	1,057	(1,239)	(216)
Total other comprehensive income (loss), net of tax	$ 1,979	$ (509)	$ 1,980	$ 1,464