Leases (Operating Lease Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Leases [Abstract]
Long-term fixed lease expense	$ 4,032	$ 8,942	$ 18,043	$ 25,507
Long-term variable lease expense	85	117	285	298
Short-term lease expense	1,652	3,346	8,175	13,216
Total operating lease expense	$ 5,769	$ 12,405	$ 26,503	$ 39,021