Subsequent Events - Additional Information (Detail) - Barclays Bank PLC [Member] - Term Loan Credit Facility [Member]		1 Months Ended
	Oct. 01, 2018	Aug. 31, 2018
Subsequent Event [Line Items]
Debt instrument floor base rate		1.00%
Debt instrument variable interest rate		2.00%
Federal Funds Effective Rate [Member]
Subsequent Event [Line Items]
Debt instrument variable interest rate		0.50%
One-Month Eurodollar [Member]
Subsequent Event [Line Items]
Debt instrument variable interest rate		1.00%
London Interbank Offered Rate (LIBOR) [Member]
Subsequent Event [Line Items]
Debt instrument variable interest rate		3.00%
Subsequent Event [Member]
Subsequent Event [Line Items]
Debt instrument floor base rate	1.00%
Debt instrument variable interest rate	3.50%
Subsequent Event [Member] | Minimum [Member]
Subsequent Event [Line Items]
Prepayment fee extended period	6 months
Subsequent Event [Member] | Maximum [Member]
Subsequent Event [Line Items]
Prepayment fee extended period	12 months
Subsequent Event [Member] | Federal Funds Effective Rate [Member]
Subsequent Event [Line Items]
Debt instrument variable interest rate	0.50%
Subsequent Event [Member] | One-Month Eurodollar [Member]
Subsequent Event [Line Items]
Debt instrument variable interest rate	1.00%
Subsequent Event [Member] | London Interbank Offered Rate (LIBOR) [Member]
Subsequent Event [Line Items]
Debt instrument variable interest rate	4.50%