DERIVATIVES - Derivative Financial Instruments, Average Remaining Maturity and the Weighted-Average Interest Rates being Paid and Received (Details) (USD $) In Thousands, unless otherwise specified			9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013 Interest Rate Swap	Sep. 30, 2013 Interest Rate Swap Pay fixed interest rate swaps with counterparty	Sep. 30, 2013 Interest Rate Swap Matched interest rate swaps Derivative Financial Instruments Receive Fixed Pay Variable	Sep. 30, 2013 Interest Rate Swap Matched interest rate swaps Derivative Financial Instruments Receive Variable Pay Fixed
Derivative [Line Items]
Notional Value	$ 916,011	$ 935,493	$ 916,011	$ 10,431	$ 452,790	$ 452,790
Average Maturity (years)			4 years 1 month	3 years	4 years 1 month	4 years 1 month
Fair Value			$ (1,196)	$ (999)	$ 12,748	$ (12,945)
Weighted-Average Rate Receive			3.89%	2.21%	4.88%	2.94%
Weighted-Average Rate Pay			3.95%	6.85%	2.94%	4.88%