Parent Company Information (Components of Condensed Comprehensive Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other comprehensive loss, net of tax:
Net unrealized (losses) gains on available for sale securities	$ (22,828)	$ 19,038	$ (45,358)
Net unrealized gains (losses) on derivative instruments	(3,136)	(12,506)	3,744
Other comprehensive loss of subsidiaries and associated companies	184,495	192,014	163,173
Other comprehensive loss, net of tax	(21,845)	(7,712)	(16,283)
Parent Company [Member]
Condensed Statement of Income Captions [Line Items]
Net income	206,340	199,726	179,456
Other comprehensive loss, net of tax:
Net unrealized (losses) gains on available for sale securities	(2,109)	725	(616)
Net unrealized gains (losses) on derivative instruments	1,223	(2,932)	1,152
Other comprehensive loss of subsidiaries and associated companies	(20,959)	(5,505)	(16,819)
Other comprehensive loss, net of tax	(21,845)	(7,712)	(16,283)
Comprehensive income	$ 184,495	$ 192,014	$ 163,173