Fair Value - Information About Our Fixed Rate Financial Instruments Not Measured at Fair Value (Detail) - Fair Value, Inputs, Level 2 [Member] - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Estimate of Fair Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loan secured by real estate	$ 0	$ 4,859
Fixed rate debt	(357,857)	(359,131)
Reported Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loan secured by real estate	0	3,574
Fixed rate debt	$ (366,571)	$ (370,348)