Accumulated Other Comprehensive Income (Loss) (Details 2) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Before-Tax
Net change	$ 7,254	$ 22,255
Tax Effect
Net change	(2,626)	(9,372)
Net-of-Tax
Other comprehensive income	4,628	12,883
Available-for-Sale Investment Securities
Before-Tax
Net unrealized gains (losses) arising during the period	8,721	26,130
Net realized gains reclassified into net income	(2,474)	(3,842)
Net change	6,247	22,288
Tax Effect
Net unrealized gains (losses) arising during the period	(3,666)	(10,988)
Net realized gains reclassified into net income	1,040	1,616
Net change	(2,626)	(9,372)
Net-of-Tax
Net unrealized gains (losses) arising during the period	5,055	15,142
Net realized gains reclassified into net income	(1,434)	(2,226)
Other comprehensive income	3,621	12,916
Foreign Currency Translation Adjustments
Before-Tax
Net unrealized gains (losses) arising during the period	1,007	(33)
Net change	1,007	(33)
Tax Effect
Net unrealized gains (losses) arising during the period	0	0
Net change	0	0
Net-of-Tax
Net unrealized gains (losses) arising during the period	1,007	(33)
Net realized gains reclassified into net income	0	0
Other comprehensive income	$ 1,007	$ (33)