Debt - Summary of Debt (Parenthetical) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Debt Disclosure [Abstract]
Proceeds on revolving credit facility	$ 70,200,000	$ 48,300,000	$ 41,800,000
Repayments on revolving credit facility	$ 67,700,000	$ 54,200,000	$ 37,800,000