Accumulated Other Comprehensive Income (Loss) (Details 2) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Before-Tax
Net change	$ 13,836	$ 3,961	$ 21,090	$ 26,216
Tax Effect
Net change	(4,499)	(3,615)	(7,125)	(12,987)
Net-of-Tax
Net unrealized gains (losses) arising during the period	10,913	1,990	16,975	17,099
Net realized gains reclassified into net income	(1,576)	(1,644)	(3,010)	(3,870)
Other comprehensive income	9,337	346	13,965	13,229
Available-for-Sale Investment Securities
Before-Tax
Net unrealized gains (losses) arising during the period	13,420	11,435	22,141	37,565
Net realized gains reclassified into net income	(2,720)	(2,836)	(5,194)	(6,678)
Net change	10,700	8,599	16,947	30,887
Tax Effect
Net unrealized gains (losses) arising during the period	(5,643)	(4,807)	(9,309)	(15,795)
Net realized gains reclassified into net income	1,144	1,192	2,184	2,808
Net change	(4,499)	(3,615)	(7,125)	(12,987)
Net-of-Tax
Net unrealized gains (losses) arising during the period	7,777	6,628	12,832	21,770
Net realized gains reclassified into net income	(1,576)	(1,644)	(3,010)	(3,870)
Other comprehensive income	6,201	4,984	9,822	17,900
Foreign Currency Translation Adjustments
Before-Tax
Net unrealized gains (losses) arising during the period	3,136	(4,638)	4,143	(4,671)
Net change	3,136	(4,638)	4,143	(4,671)
Tax Effect
Net unrealized gains (losses) arising during the period	0	0	0	0
Net change	0	0	0	0
Net-of-Tax
Net unrealized gains (losses) arising during the period	3,136	(4,638)	4,143	(4,671)
Net realized gains reclassified into net income	0	0	0	0
Other comprehensive income	$ 3,136	$ (4,638)	$ 4,143	$ (4,671)