Consolidated Statement of Equity (Statement) - USD ($) $ in Thousands	Total	Parent [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock, Common [Member]	Retained Earnings [Member]	Treasury Stock [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Shares, Issued							(38,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity Attributable to Parent		$ 2,615,538	$ 998	$ 3,387,754		$ (772,265)	$ (949)
Shares, Outstanding			99,759,000
Issuance of treasury shares					65,000
Purchase of treasury shares		(2,356)			$ (2,356)
Issuance of treasury shares		0		0	0
Net income (loss)		(9,036)				(9,036)
Stock Issued During Period, Shares, Acquisitions			0
Stock Issued During Period, Value, Acquisitions		0	$ 0	0
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture			209,000				0
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture		5,020	$ 2	3,670			$ 1,348
Treasury Stock, Shares, Retired			(33,000)				33,000
Treasury Stock, Retired, Cost Method, Amount			$ 0	(1,091)	$ 1,091
Stock Repurchased and Retired During Period, Shares			(568,000)		568,000
Stock Repurchased During Period, Value		(22,098)			$ (22,098)
Stock Repurchased and Retired During Period, Value			$ (6)	(21,061)	$ 21,067
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation					(81,000)
Stock Repurchased During Period, Shares					(598,000)
Net income (loss)	$ 49,248
Stock Repurchased During Period, Shares					(2,700,000)
Shares, Issued							(51,000)
Stockholders' Equity Attributable to Parent		2,587,068	$ 994	3,369,272		(781,301)	$ (1,897)
Shares, Outstanding			99,367,000
Issuance of treasury shares							22,000
Dividends	(12,117)
Purchase of treasury shares		(3,300)			$ (3,300)
Issuance of treasury shares				0			$ 0
Net income (loss)		(87,037)				(87,037)
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture			295,000				0
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture		6,495	$ 3	5,742			$ 750
Treasury Stock, Shares, Retired			(78,000)				78,000
Treasury Stock, Retired, Cost Method, Amount			$ (1)	(2,807)	$ 2,808
Stock Repurchased and Retired During Period, Shares			677,000		(684,000)
Stock Repurchased During Period, Value		26,509			$ 26,509
Stock Repurchased and Retired During Period, Value	$ 306		$ 7	26,922	$ (27,235)
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation					(92,000)
Stock Repurchased During Period, Shares					(661,000)
Common Stock, Dividends, Per Share, Declared	$ 0.12
Shares, Issued							(20,000)
Stockholders' Equity Attributable to Parent		2,464,906	$ 989	3,333,168		(868,338)	$ (913)
Shares, Outstanding			98,907,000
Issuance of treasury shares			0				1,000
Dividends	$ (11,936)
Purchase of treasury shares		180			$ 180
Issuance of treasury shares		0	$ 0	0			$ 0
Net income (loss)	145,321	145,321				145,321
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture			12,000				0
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture		5,779	$ 0	5,730			$ 49
Treasury Stock, Shares, Retired			2,000				(2,000)
Treasury Stock, Retired, Cost Method, Amount				91	$ (91)
Stock Repurchased and Retired During Period, Shares			1,476,000		(1,476,000)
Stock Repurchased During Period, Value		59,666			$ 59,666
Stock Repurchased and Retired During Period, Value	$ 0		$ 15	59,610	$ (59,625)
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation					4,000
Stock Repurchased During Period, Shares					(1,476,000)
Common Stock, Dividends, Per Share, Declared	$ 0.12
Shares, Issued							21,000
Stockholders' Equity Attributable to Parent		2,544,224	$ 974	3,267,261		(723,017)	$ (994)
Shares, Outstanding			97,441,000
Shares, Issued							(55,000)
Stockholders' Equity Attributable to Parent	$ 2,910,247	2,910,247	$ 965	3,161,941		(249,954)	$ (2,705)
Shares, Outstanding			96,468,000
Issuance of treasury shares					67,000
Purchase of treasury shares		(9,203)			$ (9,203)
Issuance of treasury shares		0		0	0
Net income (loss)		(31,960)				(31,960)
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture			655,000				0
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture		5,474	$ 7	1,798			$ 3,669
Treasury Stock, Shares, Retired			(53,000)				53,000
Treasury Stock, Retired, Cost Method, Amount			$ (2)	(3,022)	$ 3,024
Stock Repurchased and Retired During Period, Shares			(1,320,000)		1,320,000
Stock Repurchased During Period, Value		(85,339)			$ (85,339)
Stock Repurchased and Retired During Period, Value			$ (13)	(83,508)	$ 83,521
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation					(164,000)
Stock Repurchased During Period, Shares					(1,326,000)
Dividends, Common Stock		(24,468)		(24,468)
Common Stock, Dividends, Per Share, Declared	$ 0.25
Net income (loss)	$ 1,428,386
Stock Repurchased During Period, Shares					(8,500,000)
Dividends, Common Stock	$ 92,400
Common Stock, Dividends, Per Share, Declared	$ 0.95
Shares, Issued							(105,000)
Stockholders' Equity Attributable to Parent		2,764,751	$ 957	3,052,741		(281,914)	$ (7,033)
Shares, Outstanding			95,750,000
Issuance of treasury shares							5,000
Dividends	$ (34,658)
Purchase of treasury shares		(7,657)			$ (7,657)
Issuance of treasury shares		0		0			$ 0
Net income (loss)		662,381				662,381
Stock Issued During Period, Shares, Acquisitions			4,007,000
Stock Issued During Period, Value, Acquisitions		293,314	$ 40	293,274
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture			337,000				0
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture		7,296	$ 3	6,924			$ 369
Treasury Stock, Shares, Retired			(101,000)				101,000
Treasury Stock, Retired, Cost Method, Amount			$ (1)	(7,635)	$ 7,636
Stock Repurchased and Retired During Period, Shares			(2,946,000)		2,946,000
Stock Repurchased During Period, Value		(214,706)			$ (214,706)
Stock Repurchased and Retired During Period, Value	$ 0		$ (29)	(214,123)	$ 214,152
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation					(101,000)
Stock Repurchased During Period, Shares					(2,966,000)
Common Stock, Dividends, Per Share, Declared	$ 0.35
Shares, Issued							(120,000)
Stockholders' Equity Attributable to Parent		3,470,721	$ 970	3,096,523		380,467	$ (7,239)
Shares, Outstanding			97,047,000
Issuance of treasury shares			0				0
Dividends	$ (33,251)			0		(33,251)
Purchase of treasury shares		119			$ 119
Issuance of treasury shares		0	$ 0	0			$ 0
Net income (loss)	797,965	797,965				797,965
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture			7,000				0
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture		7,182	$ 0	7,254			$ (72)
Treasury Stock, Shares, Retired			2,000				(2,000)
Treasury Stock, Retired, Cost Method, Amount				69	$ (115)	46
Stock Repurchased and Retired During Period, Shares			(4,195,000)		4,195,000
Stock Repurchased During Period, Value		(261,151)			$ (261,151)	0
Stock Repurchased and Retired During Period, Value	$ 0		$ (41)	(153,083)	$ 261,030	(107,906)
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation					2,000
Stock Repurchased During Period, Shares					(4,205,000)
Common Stock, Dividends, Per Share, Declared	$ 0.35
Shares, Issued							130,000
Stockholders' Equity Attributable to Parent	$ 3,981,347	$ 3,981,347	$ 929	$ 2,950,625		$ 1,037,229	$ (7,436)
Shares, Outstanding			92,857,000