Disclosures About Fair Value of Assets and Liabilities - Transfer Between Levels 1, 2 and 3 and Reasons For Those Transfers (Details) (USD $)
In Thousands, unless otherwise specified

6 Months Ended

Jun. 30, 2013

Jun. 30, 2012

Significant Other Observable Inputs (Level 2)

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Transfer between Levels 1, 2 and 3

$ 12,205

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 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 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