Leases (Supplemental Cash Flow Information) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases
Cash paid for amounts included in the measurement of operating lease liabilities, operating cash flows from operating leases	$ 334,994	$ 318,048
Right-of-use asset obtained in exchange for new operating lease liability	$ 322,712	$ 233,584