Leases - Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
ROU assets:
Operating lease ROU assets	$ 53,839	$ 0
Finance lease ROU assets	59,104
Total ROU assets	112,943
Operating lease liabilities:
Current operating lease liabilities	10,575	0
Noncurrent operating lease liabilities	50,965	$ 0
Total operating lease liabilities	61,540
Finance lease liabilities:
Current finance lease liabilities	5,550
Noncurrent finance lease liabilities	32,768
Total finance lease liabilities	$ 38,318