Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Operating leases:
Right of use assets	$ 50,451
Finance leases:
Right of use asset, cost	19
Accumulated amortization	(10)
Right of use asset, net	9
Total right of use assets, net	50,460	$ 0
Current
Operating	6,928
Finance	82
Non-current
Operating	46,419
Finance	196
Total lease liabilities	$ 53,625