Derivatives and Hedging Activities - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2016 USD ($) Contract	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) Contract	Jun. 30, 2015 USD ($)
Credit Default Option [Member]
Derivative [Line Items]
Credit Risk Related Contingent Features Termination Value	$ 12,500,000		$ 12,500,000
Termination
Derivative [Line Items]
Fair Value of Credit Risk Derivatives	11,800,000		11,800,000
Net Liability Position [Member]
Derivative [Line Items]
Credit Risk Related Contingent Features Termination Value	$ 12,500,000		$ 12,500,000
Designated as Hedging Instrument [Member] | Interest Rate Caps
Derivative [Line Items]
Derivative, Number of Instruments Held | Contract	3		3
Derivative, Notional Amount	$ 75,000,000		$ 75,000,000
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Number of Instruments Held | Contract	7		7
Derivative, Notional Amount	$ 550,000,000		$ 550,000,000
Designated as Hedging Instrument [Member] | Interest Expense
Derivative [Line Items]
Loss on Cash Flow Hedge Ineffectiveness	$ (120,000)	$ (12,000)	(163,000)	$ (73,000)
Change in fair value of interest rate derivatives included in AOCI and expected to be reclassified in the next 12 months			$ 3,700,000