Derivative Instruments - Additional Information (Detail) (Interest Rate Swap Agreements [Member], USD $)	12 Months Ended
	Dec. 31, 2013 Interest_Rate_Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate swap inception date	Dec. 16, 2013
Number of forward-starting swap agreements	3
Derivative average Interest rate	2.73%
Aggregated notional amount of interest swap agreements	$ 186,000,000
Interest rate swap effective date	Dec. 31, 2015
Derivative fixed Interest rate	5.23%
Interest rate swap expiration date	Dec. 31, 2018
Change in fair value of interest rate	200,000
Unrealized gains included in accumulated other comprehensive income	0
Unrealized gains reported in earnings
Fair value of interest rate	400,000
Floating LIBOR -Based Interest [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Outstanding LIBOR-based debt	$ 186,000,000