Leases - Components of Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Leases [Abstract]
Operating lease costs	$ 29,976	$ 90,164
Amortization of lease assets	417	1,042
Interest on lease liabilities	160	318
Finance lease costs	577	1,360
Variable lease costs	174	525
Sublease income	(738)	(2,513)
Total lease costs	$ 29,989	$ 89,536