- Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Operating lease costs	$ 4,363	$ 8,635
Short-term lease costs	1,773	3,663
Other lease costs	1,602	3,088
Total lease costs	$ 7,738	$ 15,386