Consolidated Statements of Changes in Equity (Unaudited) (USD $) In Thousands	Total	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total Shareholders' Equity [Member]	Non-Controlling Interests [Member]
Balance, beginning of period at Dec. 31, 2012	$ 2,993,681	$ 4	$ 859,278	$ 2,137,541	$ (188,883)	$ 149,920	$ 2,957,860	$ 35,821
Balance, beginning of period (in shares) at Dec. 31, 2012		72,415			4,088
Net income	245,009			243,633			243,633	1,376
Other comprehensive income (loss)	(152,546)					(152,546)	(152,546)
Issuance of shares for equity compensation (in shares)		675			214
Issuance of shares for equity compensation	14,945		26,317		(11,372)		14,945
Tax effect from equity compensation, net	301		301				301
Share-based compensation	4,537		4,537				4,537
Cash dividends on common stock	(77,486)			(77,486)			(77,486)
Capital calls and distributions, net	(1,467)							(1,467)
Balance, end of period at Sep. 30, 2013	3,026,974	4	890,433	2,303,688	(200,255)	(2,626)	2,991,244	35,730
Balance, end of period (in shares) at Sep. 30, 2013		73,090			4,302
Balance, beginning of period at Dec. 31, 2013	3,054,973	4	898,586	2,349,428	(202,346)	(25,623)	3,020,049	34,924
Balance, beginning of period (in shares) at Dec. 31, 2013		73,163			4,305
Net income	229,898			228,117			228,117	1,781
Other comprehensive income (loss)	48,918					48,918	48,918
Issuance of shares for equity compensation (in shares)		801			322
Issuance of shares for equity compensation	8,225		29,728		(21,503)		8,225
Tax effect from equity compensation, net	8,176		8,176				8,176
Share-based compensation	11,815		11,815				11,815
Cash dividends on common stock	(82,207)			(82,207)			(82,207)
Capital calls and distributions, net	(2,486)							(2,486)
Balance, end of period at Sep. 30, 2014	$ 3,277,312	$ 4	$ 948,305	$ 2,495,338	$ (223,849)	$ 23,295	$ 3,243,093	$ 34,219
Balance, end of period (in shares) at Sep. 30, 2014		73,964			4,627