Reconciliation of Beginning and Ending Balance for Liabilities Measured at Fair Value on Recurring Basis Unobservable Inputs (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2019 USD ($)	[1]
Fair Value Disclosures [Abstract]
Beginning balances - Liabilities	$ 5,093
Total loss included in accumulated other comprehensive loss	15,036
Settlements included in interest expense	(1,141)
Ending balances - Liabilities	$ 18,988

[1] Represents interest rate swap liabilities.  See further discussion of interest rate swaps at Note 6.