Parent Company Only Condensed Financial Information Condensed Statement of Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net income available to common stockholders	$ 58,757	$ 67,621	$ 48,584	$ 40,891	$ 50,421	$ 42,289	$ 47,603	$ 34,790	$ 215,853	$ 175,103	$ 171,902
Other Comprehensive Income (Loss), Net of Tax									(157,317)	23,154	61,256
Comprehensive Income (Loss), Net of Tax, Attributable to Parent									58,536	198,257	233,158
Parent Company
Net income available to common stockholders									215,853	175,103	171,902
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax									(3,128)	(114)	(4,929)
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax									(1,449)	2,074	(319)
Comprehensive (Income) Loss, Net of Tax, Attributable to Noncontrolling Interest									(152,740)	21,194	66,504
Other Comprehensive Income (Loss), Net of Tax									(157,317)	23,154	61,256
Comprehensive Income (Loss), Net of Tax, Attributable to Parent									$ 58,536	$ 198,257	$ 233,158