Leases - Classification of Leases (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Assets:
Operating lease assets, net of accumulated amortization	$ 102,134	$ 99,800	$ 0
Finance lease assets, net of accumulated depreciation	1,369
Total lease assets	103,503
Liabilities:
Operating lease liabilities	114,022	$ 99,800	$ 0
Finance lease liabilities	4,975
Total lease liabilities	$ 118,997