Operating Leases Lease, Cost (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Leases [Abstract]
Operating lease expense	$ 33,596	$ 32,009
Short-term lease expense (lease duration of twelve months or less at lease commencement)	14,105	17,136
Sublease income	(26,216)	(24,129)
Lease cost	$ 21,485	$ 25,016