Leases (Operating Lease Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Leases [Abstract]
Long-term fixed lease expense	$ 10,105	$ 13,500	$ 29,433	$ 40,400
Long-term variable lease expense	400		1,640
Short-term lease expense	3,355		13,356
Total operating lease expense	$ 13,860		$ 44,429