Supplemental Balance Sheet Information Related to Leases (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Operating Leases
Right of use assets-operating leases	$ 329,328	$ 0
Operating lease liabilities	55,080	0
Operating lease liabilities noncurrent	274,248	0
Total operating lease liabilities	329,328
Finance Leases
Property and equipment	8,967,340	8,563,455
Less: accumulated depreciation	(4,008,931)	(3,715,515)
Property, plant and equipment, net, Total	4,958,409	$ 4,847,940
Current maturities of long-term debt	1,591
Long-term debt	16,790
Total finance lease liabilities	$ 18,381
Weighted Average remaining lease term, years
Operating leases	9 years 10 months 24 days
Finance leases	7 years 6 months
Weighted Average discount rate
Operating leases	4.70%
Finance leases	10.40%
Finance Lease
Finance Leases
Property and equipment	$ 23,250
Less: accumulated depreciation	(10,844)
Property, plant and equipment, net, Total	$ 12,406