Derivative Instruments and Hedging Activities - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Unrealized loss on interest rate caps, net of tax	$ 17	$ 179	$ 383	$ 356
LIBOR plus 1.5%
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, interest rate cap floor	1.50%		1.50%
LIBOR Plus 2.5%
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, interest rate cap floor	2.50%		2.50%
Interest rate caps
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Interest rate caps	$ 404		$ 404		$ 340
Unrealized loss on interest rate caps, net of tax	17	180	383	356
Unrealized gain (loss) on interest rate caps, tax	5	$ 89	130	$ 145
Interest rate caps | LIBOR plus 1.5%
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, notional amount	134,000		134,000
Interest rate caps | LIBOR Plus 2.5%
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, notional amount	$ 219,837		$ 219,837