Leases - Leases Assets and Liabilities (Details) $ in Thousands	Jun. 30, 2019 USD ($)
Assets:
Operating lease assets	$ 937,884
Finance lease assets	35,128
Total leased assets	973,012
Current
Operating	95,697
Finance	3,805
Non-current
Operating	862,369
Finance	34,252
Total lease liabilities	$ 996,123