Shareholders' Equity - Changes in Shareholders' Equity (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Jan. 01, 2019
Changes in shareholders' equity that are attributable to the Company's shareholders and to non controlling interests
Beginning Balance	$ 1,039,904	$ 1,198,919
Proceeds from exercise of stock options	$ 333	261
Proceeds from exercise of stock options (shares)	22
Stock-based compensation expense	$ 6,727	5,827
Restricted stock granted	0
Restricted stock canceled	0	0
Dividends paid	(57,945)	(58,319)
Shares withheld for net settlements of share-based awards	(4,172)	(4,357)
Issuance of common stock - ESPP	124	141
Repurchases of common stock		(40,182)
Transition adjustment for accounting standard adoption			$ 0
Net income (loss)	40,649	34,920
Other comprehensive income	2,252	1,362
Ending Balance	1,026,904	1,138,572
Common shares
Changes in shareholders' equity that are attributable to the Company's shareholders and to non controlling interests
Beginning Balance	$ 1,248	$ 1,240
Beginning Balance, shares	120,585	124,008
Proceeds from exercise of stock options	$ 0	$ 1
Proceeds from exercise of stock options (shares)	22	15
Restricted stock granted	$ 8
Restricted stock granted (shares)	778
Restricted stock canceled	$ 0	$ 0
Restricted stock canceled (shares)	(6)	(9)
Shares withheld for net settlements of share-based awards	$ (2)	$ (2)
Shares withheld for net settlements of share-based awards (shares)	(198)	(169)
Repurchases of common stock (shares)		(1,848)
Issuance of common stock - ESPP (shares)	6	8
Ending Balance	$ 1,254	$ 1,239
Ending Balance, shares	121,187	122,005
Additional Paid-In Capital
Changes in shareholders' equity that are attributable to the Company's shareholders and to non controlling interests
Beginning Balance	$ 1,210,916	$ 1,190,906
Proceeds from exercise of stock options	333	260
Stock-based compensation expense	6,727	5,827
Restricted stock granted	(8)
Shares withheld for net settlements of share-based awards	(4,170)	(4,355)
Issuance of common stock - ESPP	124	141
Ending Balance	1,213,922	1,192,779
Earnings in Excess of Distributions
Changes in shareholders' equity that are attributable to the Company's shareholders and to non controlling interests
Beginning Balance	(52,868)	31,541
Dividends paid	(57,945)	(58,319)
Transition adjustment for accounting standard adoption			(968)
Net income (loss)	40,705	34,987
Ending Balance	(71,076)	8,209
Accumulated Other Comprehensive Loss
Changes in shareholders' equity that are attributable to the Company's shareholders and to non controlling interests
Beginning Balance	(23,618)	(24,446)
Transition adjustment for accounting standard adoption			$ 968
Other comprehensive income		1,354
Ending Balance	(21,366)	(23,092)
Treasury shares
Changes in shareholders' equity that are attributable to the Company's shareholders and to non controlling interests
Beginning Balance	$ (95,175)	$ 0
Beginning Balance, shares	4,210	0
Repurchases of common stock (shares)		1,848
Repurchases of common stock		$ (40,182)
Ending Balance	$ (95,175)	$ (40,182)
Ending Balance, shares	4,210	1,848
Noncontrolling Interests
Changes in shareholders' equity that are attributable to the Company's shareholders and to non controlling interests
Beginning Balance	$ (599)	$ (322)
Net income (loss)	(56)	(67)
Other comprehensive income		8
Ending Balance	(655)	$ (381)
Accounting Standards Update 2016-02
Changes in shareholders' equity that are attributable to the Company's shareholders and to non controlling interests
Other comprehensive income	1,284
Accounting Standards Update 2016-02 | Accumulated Other Comprehensive Loss
Changes in shareholders' equity that are attributable to the Company's shareholders and to non controlling interests
Other comprehensive income	1,284
Accounting Standards Update 2016-02 | Noncontrolling Interests
Changes in shareholders' equity that are attributable to the Company's shareholders and to non controlling interests
Other comprehensive income	$ 0