Leases (Lease Expense) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Leases [Abstract]
Operating lease expense	$ 6,098	$ 17,148
Variable lease expenses	225	901
Short-term and other lease expenses	190	1,144
Total lease expense	$ 6,513	$ 19,193