Fair Value of Financial Instruments - Transfer Between Levels 1, 2 and 3 and Reasons For Those Transfers (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Reason for Transfer	The interest rate swap and cap instruments were transferred from Level 3 to Level 2 as of March 31, 2012 due to the availability of additional valuation information. These instruments are valued using widely accepted valuation techniques including discounted cash flow analysis using observable inputs such as contractual terms and LIBOR-based rate curves.
Significant Other Observable Inputs (Level 2) | Interest rate swap liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfer between Levels 1, 2 and 3	6,934
Significant Other Observable Inputs (Level 2) | Interest rate swap asset
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfer between Levels 1, 2 and 3	4,862
Significant Other Observable Inputs (Level 2) | Interest rate cap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfer between Levels 1, 2 and 3	409
Significant Unobservable Inputs (Level 3) | Interest rate swap liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfer between Levels 1, 2 and 3	(6,934)
Significant Unobservable Inputs (Level 3) | Interest rate swap asset
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfer between Levels 1, 2 and 3	(4,862)
Significant Unobservable Inputs (Level 3) | Interest rate cap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfer between Levels 1, 2 and 3	(409)