Derivative Instruments and Hedging Activities - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015 USD ($) Swap	Dec. 31, 2014 USD ($)	Jun. 30, 2015 USD ($) Swap
Derivative Instruments, Gain (Loss) [Line Items]
Loss related to ineffective portion of derivatives recognized in other expense (income), net	$ 287,000	$ 0
Reclassified as an increase to interest expense, expected during the next 12 months	5,299,000
Unrealized loss on derivatives, tax benefit	6,115,000	286,000
Termination value of derivatives in a net liability position	21,529,000
Collateral posted relating to credit risk-related contingent features	0
Forward Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of interest rate swap			$ 1,000,000,000
Number of interest rate swaps held | Swap			5
Combined Interest Rate Cash Flow Hedges, All Swaps [Member] | Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of interest rate swap	$ 1,250,000,000
Number of interest rate swaps held | Swap	4
Combined Interest Rate Cash Flow Hedges, All Swaps [Member] | Forward Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of interest rate swap	$ 1,000,000,000
Number of interest rate swaps held | Swap	5
Not Designated as Hedge Accounting Relationships [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives outstanding	$ 0	$ 0