Fair Value Measurements - Estimate of the Fair Value of Financial Instruments Not Recorded at Fair Value on Balance Sheet (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Fair Value, Level 1
Financial Assets:
Portfolio loans, net	$ 0	$ 0
Financial Liabilities:
Deposits	1,926,899	1,974,432
Subordinated debentures	0	0
Federal Home Loan Bank advances	0	0
Other borrowings	0	0
Fair Value, Level 2
Financial Assets:
Portfolio loans, net	0	0
Financial Liabilities:
Deposits	0	0
Subordinated debentures	0	0
Federal Home Loan Bank advances	0	0
Other borrowings	0	0
Fair Value, Level 3
Financial Assets:
Portfolio loans, net	2,162,792	2,163,723
Financial Liabilities:
Deposits	688,953	829,612
Subordinated debentures	42,110	42,252
Federal Home Loan Bank advances	88,955	110,575
Other borrowings	132,488	154,561
Estimated fair value
Financial Assets:
Portfolio loans, net	2,162,792	2,163,723
Financial Liabilities:
Deposits	2,615,852	2,804,044
Subordinated debentures	42,110	42,252
Federal Home Loan Bank advances	88,955	110,575
Other borrowings	$ 132,488	$ 154,561