Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Earnings in Excess of Distributions	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Noncontrolling Interest
Beginning Balance at Dec. 31, 2013	$ 1,023,976	$ 866	$ 848,018	$ 232,646	$ (4,429)	$ (53,579)	$ 454
Beginning Balance, Shares at Dec. 31, 2013		72,082				14,580
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Proceeds from stock options exercised	7,281	$ 4	7,277
Proceeds from stock options exercised, Shares		386
Tax benefit related to equity compensation	2,035		2,035
Stock based compensation expense	8,909		8,909
Shares withheld for net settlements of share-based awards, shares		(54)				43
Shares withheld for net settlements of share-based awards	(1,844)		(428)			$ (1,416)
Restricted stock granted	0	$ 3	(3)
Restricted stock granted, Shares		306
Purchase and retirement of common stock	0	$ (146)	(54,826)			$ 54,972
Purchase and retirement of common stock, Shares		0				(14,618)
Restricted stock cancelled	0
Restricted stock cancelled, Shares		(23)
Dividends - Paid	(170,234)			(170,234)
Issuance of common stock under prospectus supplement	54,725	$ 15	54,710	0		$ 0
Issuance of common stock under prospectus supplement, shares		1,483				0
Re-issuance of treasury shares (ESPP), Shares		11				(5)
Re-issuance of treasury shares (ESPP)	387		364	0		$ 23
Net income (loss)	143,840			143,930			(90)
Other comprehensive income (loss), net of tax	(23,082)				(23,032)		(50)
Ending Balance at Dec. 31, 2014	1,045,993	$ 742	866,056	206,342	(27,461)	$ 0	314
Ending Balance, Shares at Dec. 31, 2014		74,191				0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Proceeds from stock options exercised	2,775	$ 1	2,774
Proceeds from stock options exercised, Shares		123
Tax benefit related to equity compensation	1,409		1,409
Stock based compensation expense	11,709		11,709
Shares withheld for net settlements of share-based awards, shares		(72)				0
Shares withheld for net settlements of share-based awards	(2,786)		(2,786)			$ 0
Restricted stock granted	0	$ 4	(4)
Restricted stock granted, Shares		423
Restricted stock cancelled	0
Restricted stock cancelled, Shares		(35)
Dividends - Paid	(186,984)			(186,984)
Re-issuance of treasury shares (ESPP), Shares		13				0
Re-issuance of treasury shares (ESPP)	441		441	0		$ 0
Net income (loss)	139,315			139,438			(123)
Other comprehensive income (loss), net of tax	(5,035)				(4,943)		(92)
Ending Balance at Dec. 31, 2015	1,006,837	$ 747	879,599	158,796	(32,404)	$ 0	99
Ending Balance, Shares at Dec. 31, 2015		74,643				0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Proceeds from stock options exercised	$ 3,347	$ 1	3,346
Proceeds from stock options exercised, Shares	155	156
Tax benefit related to equity compensation	$ (1,626)		(1,626)
Stock based compensation expense	12,773		12,773
Shares withheld for net settlements of share-based awards, shares		(75)
Shares withheld for net settlements of share-based awards	(2,337)	$ (1)	(2,336)
Restricted stock granted	0	$ 3	(3)
Restricted stock granted, Shares		349
Restricted stock cancelled	0	$ 0
Restricted stock cancelled, Shares		(56)
Dividends - Paid	(194,748)			(194,748)
Shares issued for ESPP		15
Issuance of common stock (ESPP)	436		436
Other adjustments to Additional Paid-In-Capital	179		179
Net income (loss)	148,498			148,715			(217)
Other comprehensive income (loss), net of tax	1,598				1,579		19
Ending Balance at Dec. 31, 2016	$ 974,957	$ 750	$ 892,368	$ 112,763	$ (30,825)	$ 0	$ (99)
Ending Balance, Shares at Dec. 31, 2016		75,032				0