Leases - Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease costs (a)	$ 136,842	$ 142,100
Short-term and variable lease cost	42,300	43,800
Sublease rental income	$ 2,697	$ 5,690