Components of Lease Expense (Detail) - USD ($) $ in Thousands		3 Months Ended	9 Months Ended
		Sep. 30, 2019	Sep. 30, 2019
Leases [Abstract]
Operating lease cost		$ 17,849	$ 54,188
Variable and short term lease cost	[1]	9,811	26,132
Total lease cost		27,660	80,320
Finance lease cost:
Amortization of right-of-use-assets		481	1,444
Interest on lease liabilities		464	1,422
Total finance lease cost		$ 945	$ 2,866

[1] Includes equipment, month-to-month and leases with a maturity of less than 12 months.