Commitments and Contingencies (Additional Information) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Jun. 30, 2017	Nov. 30, 2013
Debt Instrument [Line Items]
Operating lease costs	$ 14,700,000
Lease expenses recognized prior to adoption of Topic 842		$ 11,400,000
Cash paid for operating lease liability	10,000,000.0
Operating lease liability from obtaining operating right-of-use assets	$ 67,700,000
Weighted-average lease remaining lease term	10 years 6 months
Weighted-average discount rate	3.90%
Undiscounted cash flows	$ 413,400,000
Unrecognized tax benefits	4,800,000
Letters of credit	21,300,000
2022 Notes
Debt Instrument [Line Items]
Face amount of debt	$ 782,500,000		$ 782,500,000	$ 782,500,000
2018 Notes
Debt Instrument [Line Items]
Face amount of debt					$ 575,000,000.0
Minimum
Debt Instrument [Line Items]
Lessee, Operating Lease, Lease Not yet Commenced, Term of Contract	3 years
Maximum
Debt Instrument [Line Items]
Lessee, Operating Lease, Lease Not yet Commenced, Term of Contract	15 years