Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Provisional tax expense		$ 26,000
Transition tax expense	$ 5,500	43,400
Change in tax rate benefit	2,400	17,400
Valuation allowance	2,824	0
Foreign earnings repatriated	621,500
Unrecognized tax benefits including accrued interest and penalties	67,800	90,700	$ 77,100
Unrecognized tax benefits, income tax penalties and interest accrued	11,800	10,700	13,700
Income tax interest and penalties expense	1,300	$ 2,300	$ 3,900
Unrecognized tax benefits that, if recognized, would impact the effective income tax rate	67,800
Unrecognized tax benefits that may be recognized	33,200
Estimate of possible charge	$ 35,000