Commitments and Contingencies (Lease Income From Operating Leases) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Lease income and rental expense from operating leases
Rental and service income - operating leases	$ 96,036	$ 90,333	$ 95,254
Rental expense	$ 15,702	$ 16,459	$ 16,723