Supplemental Balance Sheet Information Related to Leases (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Operating Leases
Right of use assets-operating leases	$ 332,135	$ 0
Operating lease liabilities	56,447	0
Operating lease liabilities noncurrent	275,688	0
Total operating lease liabilities	332,135
Finance Leases
Property and equipment	8,859,104	8,563,455
Less: accumulated depreciation	(3,914,406)	(3,715,515)
Property, plant and equipment, net, Total	4,944,698	$ 4,847,940
Current maturities of long-term debt	1,664
Long-term debt	17,206
Total finance lease liabilities	$ 18,870
Weighted Average remaining lease term, years
Operating leases	10 years
Finance leases	7 years 7 months 6 days
Weighted Average discount rate
Operating leases	4.70%
Finance leases	10.40%
Finance Lease
Finance Leases
Property and equipment	$ 23,250
Less: accumulated depreciation	(10,363)
Property, plant and equipment, net, Total	$ 12,887