Fair Value - Information About Our Fixed Rate Financial Instruments Not Measured at Fair Value (Detail) (Fair Value, Inputs, Level 2 [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
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	(369,112)	(370,348)
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	$ (357,342)	$ (359,131)