Leases (Summary of Lease Costs) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Leases [Abstract]
Operating lease costs	$ 33,184
Finance lease costs:
Amortization of leased assets	2,472
Interest on lease liabilities	2,513
Short term lease costs	3,309
Variable lease costs	1,068
Total net lease costs	$ 42,546