Accounting for Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018
Income Tax Contingency [Line Items]
Provision for income taxes	$ 25,895	$ 24,601	$ 77,812	$ 35,206
Effective income tax rate, continuing operations	20.20%	19.40%	19.10%	10.20%
Effective Income Tax Rate Reconciliation, Excess Tax Benefit Amount			$ 400	$ 13,500
Unrecognized tax benefits	$ 46,000		46,000			$ 33,300
Accrued penalties and interest	$ 1,600		$ 1,600
Undistributed earnings of foreign subsidiaries						533,500
Amount of no longer indefinitely reinvested foreign earnings						239,200
Amount of indefinitely reinvested foreign earnings						$ 294,300
National Corporate Tax Rate						30.00%
Scenario, Forecast | Subsequent Event
Income Tax Contingency [Line Items]
National Corporate Tax Rate					30.00%