Other Noncurrent Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Liabilities, Noncurrent [Abstract]
Transition tax on foreign earnings	$ 394,878	$ 0
Liabilities related to uncertain tax positions	24,369	27,919
Executive deferred compensation plan obligation	25,494	22,037
Environmental liabilities	37,518	32,595	$ 29,993
Asset retirement obligations	40,450	36,296
Tax indemnification liability	42,707	38,255
Other	33,758	37,708
Total	$ 599,174	$ 194,810