Leases - Summary of Balance Sheet Classifications of Operating and Finance Leases (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Operating Leases:
Operating lease right-of-use assets	$ 498,233
Current operating lease liabilities	50,776
Noncurrent operating lease liabilities	446,128
Total operating lease liabilities	496,904
Finance Leases:
Property, plant and equipment	11,143
Accumulated depreciation	(935)
Property, plant and equipment, net	10,208
Other current liabilities	3,456	$ 3,249
Other noncurrent liabilities	7,862	7,630
Total finance lease liabilities	$ 11,318	$ 10,879