Leases - Lessee Disclosure, Balance Sheet Disclosure (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Assets:
Operating lease assets	$ 182,311	$ 184,648
Total lease assets	182,311	184,648
Current
Operating	20,001	20,318	$ 0
Noncurrent
Operating	166,453	170,190
Total lease liabilities	$ 186,454	$ 190,508