Consolidated Statements of Changes in Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income [Member]	Total Shareholders' Equity [Member]	Non-Controlling Interests [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period		24
Balance, beginning of period (in shares) at Dec. 31, 2015		74,530			8,636
Balance, beginning of period at Dec. 31, 2015	$ 3,267,639	$ 4	$ 982,009	$ 2,704,121	$ (477,165)	$ 21,587	$ 3,230,556	$ 37,083
Net income (loss)	40,988			42,564			42,564	(1,576)
Other comprehensive income	71,522					71,522	71,522
Stock Issued During Period, Value, Stock Options Exercised			1,191
Stock options exercised	1,191						1,191
Non-vested shares awarded, net (in shares)		247
Vesting of non-vested shares (in shares)					10
Vesting of non-vested shares	(260)				$ (260)		(260)
Tax effect from equity compensation, net	1,816		1,816				1,816
Share-based compensation	2,030		2,030				2,030
Cash dividends on common stock	(28,384)			(28,384)			(28,384)
Capital calls and distributions, net	(797)							(797)
Balance, end of period (in shares) at Mar. 31, 2016		74,801			8,646
Balance, end of period at Mar. 31, 2016	3,356,265	$ 4	987,046	2,718,301	$ (476,905)	93,109	3,321,555	34,710
Balance, beginning of period (in shares) at Dec. 31, 2016		74,993			9,656
Balance, beginning of period at Dec. 31, 2016	3,306,357	$ 4	1,006,535	2,823,334	$ (544,052)	(10,967)	3,274,854	31,503
Net income (loss)	88,664			88,356			88,356	308
Other comprehensive income	5,746					5,746	5,746
Stock options exercised (in shares)		27
Stock options exercised	1,222		1,222				1,222
Non-vested shares awarded, net (in shares)		61
Vesting of non-vested shares (in shares)					17
Vesting of non-vested shares	(1,389)				$ (1,389)		(1,389)
Share-based compensation	1,603		1,603				1,603
Cash dividends on common stock	(28,648)			(28,648)			(28,648)
Capital calls and distributions, net	(2,661)							(2,661)
Balance, end of period (in shares) at Mar. 31, 2017		75,081			9,673
Balance, end of period at Mar. 31, 2017	$ 3,370,894	$ 4	$ 1,009,360	$ 2,883,042	$ (545,441)	$ (5,221)	$ 3,341,744	$ 29,150