Statement of Shareholders' Equity - USD ($)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Treasury Stock [Member]	Noncontrolling Interest [Member]
Common Stock, Shares, Outstanding at Dec. 31, 2013		46,750,002				1,648,613
Common Stock, Value, Issued at Dec. 31, 2013	$ 169,389,000	$ 1,203,000	$ 0	$ 415,930,000	$ (8,626,000)	$ (245,184,000)	$ 6,066,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures		0				(216,395)
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures	20,470,000	$ 0	1,295,000	(12,683,000)	0	$ 31,858,000	0
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation	3,020,000	0	3,020,000	0	0	0	0
Stock Repurchased During Period, Value	(264,368,000)	$ 0	0	0	0	$ (264,368,000)	0
Stock Repurchased During Period, Shares		0				1,680,800
Dividends	(89,089,000)	$ 0	0	(89,089,000)	0	$ 0	0
Proceeds from Issuance of Common Stock	0
Treasury Stock, Retired, Cost Method, Amount	0	$ (29,000)	(4,315,000)	(155,737,000)	0	$ 160,081,000	0
Treasury Stock, Shares, Retired		(1,150,000)				(1,150,000)
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	(787,000)	$ 0	0	0	0	$ 0	(787,000)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]
Other Comprehensive Income (Loss), Net of Tax	3,268,000	0	0	0	(3,268,000)	0	0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	258,626,000	0	0	257,485,000	0	0
Net Income (Loss) Attributable to Noncontrolling Interest	1,141,000						1,141,000
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	255,358,000
Common Stock, Value, Issued Period End at Dec. 31, 2014	93,993,000	$ 1,174,000	0	415,906,000	(11,894,000)	$ (317,613,000)	6,420,000
Common Stock, Shares, Outstanding Period End at Dec. 31, 2014		45,600,002				1,963,018
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures		0				(183,455)
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures	21,279,000	$ 0	3,267,000	(11,044,000)	0	$ 29,056,000	0
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation	(175,000)	0	(175,000)	0	0	0	0
Stock Repurchased During Period, Value	(159,709,000)	$ 0	0	0	0	$ (159,709,000)	0
Stock Repurchased During Period, Shares		0				1,444,534
Dividends	(94,235,000)	$ 0	0	(94,235,000)	0	$ 0	0
Proceeds from Issuance of Common Stock	0
Treasury Stock, Retired, Cost Method, Amount	0	$ (32,000)	(3,092,000)	(206,267,000)	0	$ 209,391,000	0
Treasury Stock, Shares, Retired		(1,250,000)				(1,250,000)
Stockholders' Equity, Other	(1,140,000)
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders		$ 0	0	0	0	$ 0	(1,140,000)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]
Other Comprehensive Income (Loss), Net of Tax	(1,356,000)	0	0	0	1,356,000	0	0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	114,932,000	0	0	114,847,000	0	0
Net Income (Loss) Attributable to Noncontrolling Interest	85,000						85,000
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	116,288,000
Common Stock, Value, Issued Period End at Dec. 31, 2015	$ (23,699,000)	$ 1,142,000	0	219,207,000	(10,538,000)	$ (238,875,000)	5,365,000
Common Stock, Shares, Outstanding Period End at Dec. 31, 2015	42,375,905	44,350,002				1,974,097
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures		0				(141,106)
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures	$ 22,079,000	$ 0	(197,000)	0	0	$ 22,276,000	0
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation	(1,162,000)	0	(1,162,000)	0	0	0	0
Stock Repurchased During Period, Value	(7,161,000)	$ 0	0	0	0	$ (7,161,000)	0
Stock Repurchased During Period, Shares		0				62,000
Dividends	(95,145,000)	$ 0	0	(95,145,000)	0	$ 0	0
Stock Issued During Period, Shares, New Issues		1,696,250				0
Proceeds from Issuance of Common Stock	197,202,000	$ 38,000	197,164,000	0	0	$ 0	0
Treasury Stock, Retired, Cost Method, Amount	$ 0	$ (32,000)	(142,955,000)	0	0	$ 142,987,000	0
Treasury Stock, Shares, Retired	1,250,000	(1,250,000)				(1,250,000)
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	$ (1,386,000)	$ 0	0	0	0	$ 0	(1,386,000)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]
Other Comprehensive Income (Loss), Net of Tax	(710,000)	0	0	0	710,000	0	0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	63,859,000	0	0	63,895,000	0	0
Net Income (Loss) Attributable to Noncontrolling Interest	(36,000)						(36,000)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	64,569,000
Common Stock, Value, Issued Period End at Dec. 31, 2016	$ 155,297,000	$ 1,148,000	$ 52,850,000	$ 187,957,000	$ (9,828,000)	$ (80,773,000)	$ 3,943,000
Common Stock, Shares, Outstanding Period End at Dec. 31, 2016	44,151,261	44,796,252				644,991