Equity and Accumulated Other Comprehensive Income (Loss) - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 1,403,404	$ 1,217,536
Total other comprehensive income (loss)	13,816	19,347
Ending balance	1,408,929	1,237,029
Defined Benefit Pension
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	1,138	(1,425)
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive income (loss)	230	24
Total other comprehensive income (loss)	230	24
Ending balance	1,368	(1,401)
Foreign Currency Translation
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	5,124	(659)
Other comprehensive income (loss) before reclassifications	13,586	19,323
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Total other comprehensive income (loss)	13,586	19,323
Ending balance	18,710	18,664
Total
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	6,262	(2,084)
Other comprehensive income (loss) before reclassifications	13,586	19,323
Amounts reclassified from accumulated other comprehensive income (loss)	230	24
Total other comprehensive income (loss)	13,816	19,347
Ending balance	$ 20,078	$ 17,263