Leases - Lease Cost and Other Information (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019 USD ($)
Cash Flow, Operating Activities, Lessee [Abstract]
Cash paid for operating lease liabilities	$ 39,291
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 19,823
Weighted average remaining lease term:
Operating leases (in years)	3 years 1 month 6 days
Operating Leases, Weighted Average Discount Rate, Percent [Abstract]
Operating leases (percent)	3.50%