Fair Value Measurements - Fair Value Measurements, Nonrecurring (Details) (Fair Value, Measurements, Nonrecurring [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Change in Fair Value, Gains (Losses) in Period	$ (17,674)		$ (26,032)
Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Change in Fair Value, Gains (Losses) in Period	(15,276)		(21,330)
Other real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Change in Fair Value, Gains (Losses) in Period	(2,398)		(4,702)
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	0	[1]	0	[1]
Quoted Prices in Active Markets for Identical Assets (Level 1) | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	[1]	0	[1]
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate	0	[1]	0	[1]
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	0	[1]	0	[1]
Significant Other Observable Inputs (Level 2) | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	[1]	0	[1]
Significant Other Observable Inputs (Level 2) | Other real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate	0	[1]	0	[1]
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	20,817	[1]	30,309	[1]
Significant Unobservable Inputs (Level 3) | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	9,068	[1]	15,927	[1]
Significant Unobservable Inputs (Level 3) | Other real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate	11,749	[1]	14,382	[1]
Total Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	20,817	[1]	30,309	[1]
Total Fair Value | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	9,068	[1]	15,927	[1]
Total Fair Value | Other real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate	$ 11,749	[1]	$ 14,382	[1]

[1] The amounts represent only balances measured at fair value during the period and still held as of the reporting date.