Leases (Supplemental Cash Flow Information) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Leases.
Cash paid for amounts included in the measurement of operating lease liabilities, operating cash flows from operating leases	$ 165,665	$ 157,372
Right-of-use asset obtained in exchange for new operating lease liability	$ 125,160	$ 79,018