Leases (Maturity Schedule) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
Lessee, Operating Lease, Liability, to be Paid, Year One	$ 92,756
Lessee, Operating Lease, Liability, to be Paid, Year Two	73,936
Lessee, Operating Lease, Liability, to be Paid, Year Three	66,328
Lessee, Operating Lease, Liability, to be Paid, Year Four	58,726
Lessee, Operating Lease, Liability, to be Paid, Year Five	51,134
Thereafter	130,429
Total lease payments	473,309
Less: imputed interest	(54,662)
Total lease liabilities	418,647
Less: current obligations	(65,466)	$ (64,019)
Operating Lease, Liability, Noncurrent	$ 353,181	$ 371,507