Leases - Lease Costs and Other Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Leases [Abstract]
Operating lease cost	$ 14,930
Short-term lease cost	1,360
Variable lease cost	2,989
Total lease costs	19,279
Cash paid for operating leases	18,574
Right-of-use assets obtained in exchange for operating lease liabilities	$ 177,509
Weighted average remaining lease term (in years)	5 years 8 months 12 days
Weighted average discount rate (percent)	4.70%