Fair Value of Financial Instruments - Carrying Amounts and Fair Values of Financial Instruments Measured based on Level Two Inputs (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Secured debt	$ 335,792	$ 277,745
Carrying Value [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Secured debt	335,792	277,745
Interest rate swap liabilities	11	16
Interest rate cap assets	370	102
Fair Value [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Secured debt	342,414	273,310
Interest rate swap liabilities	11	16
Interest rate cap assets	$ 370	$ 102