Leases - Lease Costs and Other Information (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)
Leases [Abstract]
Operating lease cost	$ 14,749	$ 29,679
Short-term lease cost	387	1,747
Variable lease cost	4,300	7,289
Total lease costs	$ 19,436	38,715
Cash paid for operating leases		33,729
Right-of-use assets obtained in exchange for operating lease liabilities		$ 190,102
Weighted average remaining lease term (in years)	5 years 6 months	5 years 6 months
Weighted average discount rate (percent)	4.80%	4.80%