Shareholders' Equity - Changes in Shareholders' Equity (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Jan. 01, 2019
Changes in shareholders' equity that are attributable to the Company's shareholders and to non controlling interests
Beginning Balance	$ 996,048	$ 1,039,904
Proceeds from exercise of stock options		333
Stock-based compensation expense	9,768	6,727
Dividends paid	(57,703)	(57,945)
Other adjustment to additional paid-in capital	8,925
Purchase of treasury shares	(9,009)
Shares withheld for net settlements of share- based awards	(2,632)	(4,172)
Issuance of common stock - ESPP	150	124
Net income (loss)	25,121	40,649
Other comprehensive income (loss)	(13,212)	2,252
Ending Balance	957,456	1,026,904
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 (loss)		1,284
Common shares
Changes in shareholders' equity that are attributable to the Company's shareholders and to non controlling interests
Beginning Balance	$ 1,254	$ 1,248
Beginning Balance (shares)	121,225	120,585
Proceeds from exercise of stock options (shares)		22
Restricted stock granted	$ 9	$ 8
Restricted stock granted (shares)	900	778
Restricted stock canceled (shares)	(21)	(6)
Purchase of treasury shares (in shares)	(554)
Shares withheld for net settlements of share- based awards	$ (2)	$ (2)
Shares withheld for net settlements of share-based awards (shares)	(174)	(198)
Issuance of common stock - ESPP	$ 1
Issuance of common stock - ESPP (shares)	10	6
Ending Balance	$ 1,262	$ 1,254
Ending Balance (shares)	121,386	121,187
Additional Paid-In Capital
Changes in shareholders' equity that are attributable to the Company's shareholders and to non controlling interests
Beginning Balance	$ 1,230,865	$ 1,210,916
Proceeds from exercise of stock options		333
Stock-based compensation expense	9,768	6,727
Restricted stock granted	(9)	(8)
Other adjustment to additional paid-in capital	8,925
Shares withheld for net settlements of share- based awards	(2,630)	(4,170)
Issuance of common stock - ESPP	149	124
Ending Balance	1,247,068	1,213,922
Distributions in Excess of Earnings
Changes in shareholders' equity that are attributable to the Company's shareholders and to non controlling interests
Beginning Balance	(119,779)	(52,868)
Dividends paid	(57,703)	(57,945)
Net income (loss)	25,181	40,705
Ending Balance	(152,301)	(71,076)
Distributions in Excess of Earnings | Accounting Standards Update 2018-02
Changes in shareholders' equity that are attributable to the Company's shareholders and to non controlling interests
Transition adjustment for accounting standard adoption			$ (968)
Accumulated Other Comprehensive Loss
Changes in shareholders' equity that are attributable to the Company's shareholders and to non controlling interests
Beginning Balance	(20,335)	(23,618)
Other comprehensive income (loss)	(13,164)
Ending Balance	(33,499)	(21,366)
Accumulated Other Comprehensive Loss | Accounting Standards Update 2018-02
Changes in shareholders' equity that are attributable to the Company's shareholders and to non controlling interests
Transition adjustment for accounting standard adoption			$ 968
Accumulated Other Comprehensive Loss | 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 (loss)		1,284
Treasury shares
Changes in shareholders' equity that are attributable to the Company's shareholders and to non controlling interests
Beginning Balance	$ (95,175)	$ (95,175)
Beginning Balance (shares)	4,210	4,210
Purchase of treasury shares	$ (9,009)
Purchase of treasury shares (in shares)	554
Ending Balance	$ (104,184)	$ (95,175)
Ending Balance (shares)	4,764	4,210
Noncontrolling Interests
Changes in shareholders' equity that are attributable to the Company's shareholders and to non controlling interests
Beginning Balance	$ (782)	$ (599)
Net income (loss)	(60)	(56)
Other comprehensive income (loss)	(48)
Ending Balance	$ (890)	$ (655)