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	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended			3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Significant Other Observable Inputs (Level 2)	Sep. 30, 2013 Significant Other Observable Inputs (Level 2)	Sep. 30, 2013 Significant Other Observable Inputs (Level 2) Available-for-sale securities	Sep. 30, 2013 Significant Other Observable Inputs (Level 2) Interest rate swap asset	Sep. 30, 2013 Significant Other Observable Inputs (Level 2) Interest rate cap	Sep. 30, 2013 Significant Other Observable Inputs (Level 2) Interest rate swap liability	Sep. 30, 2013 Significant Unobservable Inputs (Level 3)	Sep. 30, 2013 Significant Unobservable Inputs (Level 3)	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) Available-for-sale securities	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) Interest rate swap asset	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) Interest rate cap	Sep. 30, 2013 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			$ (3,905)	$ 12,205	$ (3,905)	$ 4,862	$ 409	$ 6,934	$ 3,905	$ (12,205)	$ 3,905	$ (4,862)	$ (409)	$ (6,934)
Reason for Transfer	Selected state and municipal securities were transferred from Level 2 to Level 3 due to limited availability of similar securities in active markets.	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.