Nature of Business and Summary of Significant Accounting Policies - Cumulative Effect of the Changes from Adoption of Topic 606 (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017	Jan. 01, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cumulative adjustment		$ 269,776		$ 1,123
Other current assets	$ 274,857	241,029	$ 232,027
Other assets	533,252	421,328	241,750
Other current liabilities	126,995	143,699	159,914
Other liabilities	629,763	598,659	661,710
Accumulated other comprehensive loss	(945,702)	(787,119)	(785,189)
Retained earnings	889,948	522,465	$ 252,689
Accounting Standards Update 2014-09 | Difference between revenue guidance in effect before and after Topic 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cumulative adjustment		269,800
Other current assets	(9,830)	9,002
Other assets	(192,306)	179,578
Other current liabilities	17,916	(16,215)
Other liabilities	73,414	(63,051)
Accumulated other comprehensive loss	7,846	(1,930)
Retained earnings	$ (300,495)	$ 269,776