Fair Value (Valuation Techniques) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Mortgage interest rate lock agreements | Discounted cash flow
Fair Value Inputs [Abstract]
Pull through rates	85.00%	85.00%
Mortgage interest rate lock agreements | Discounted cash flow | Weighted Average
Fair Value Inputs [Abstract]
Pull through rates	85.00%	85.00%
Mortgage forward sale agreements | Consensus pricing
Fair Value Inputs [Abstract]
Pull through rates	85.00%	85.00%
Mortgage forward sale agreements | Consensus pricing | Weighted Average
Fair Value Inputs [Abstract]
Pull through rates	85.00%	85.00%
Interest rate swap | Discounted cash flow | Minimum
Fair Value Inputs [Abstract]
Discount rate	0.33%	0.31%
Interest rate swap | Discounted cash flow | Maximum
Fair Value Inputs [Abstract]
Discount rate	0.96%	0.83%
Interest rate swap | Discounted cash flow | Weighted Average
Fair Value Inputs [Abstract]
Discount rate	0.55%	0.52%
Collateralized debt obligations | Discounted cash flow | Minimum
Fair Value Inputs [Abstract]
Discount rate	15.00%	15.00%
Default rates	0.25%	0.25%
Collateralized debt obligations | Discounted cash flow | Maximum
Fair Value Inputs [Abstract]
Discount rate	20.00%	20.00%
Default rates	0.53%	0.98%
Collateralized debt obligations | Discounted cash flow | Weighted Average
Fair Value Inputs [Abstract]
Discount rate	17.27%	17.30%
Default rates	0.31%	0.45%
Impaired loans | Consensus pricing | Minimum
Fair Value Inputs [Abstract]
Adjustments for market conditions since appraisal	1,000	1,000
Impaired loans | Consensus pricing | Maximum
Fair Value Inputs [Abstract]
Adjustments for market conditions since appraisal	170,000	956,000
Impaired loans | Consensus pricing | Weighted Average
Fair Value Inputs [Abstract]
Adjustments for market conditions since appraisal	40,000	96,000
Loan foreclosures | Consensus pricing | Minimum
Fair Value Inputs [Abstract]
Adjustments for market conditions since appraisal	5,000	2,000
Loan foreclosures | Consensus pricing | Maximum
Fair Value Inputs [Abstract]
Adjustments for market conditions since appraisal	110,000	292,000
Loan foreclosures | Consensus pricing | Weighted Average
Fair Value Inputs [Abstract]
Adjustments for market conditions since appraisal	42,000	97,000
Other real estate | Consensus pricing | Minimum
Fair Value Inputs [Abstract]
Adjustments for market conditions since appraisal	5,000	1,000
Other real estate | Consensus pricing | Maximum
Fair Value Inputs [Abstract]
Adjustments for market conditions since appraisal	165,000	631,000
Other real estate | Consensus pricing | Weighted Average
Fair Value Inputs [Abstract]
Adjustments for market conditions since appraisal	46,000	95,000
Level 3 | Mortgage interest rate lock agreements | Discounted cash flow
Fair Value Inputs [Abstract]
Assets, Fair Value	47	86
Level 3 | Mortgage forward sale agreements | Consensus pricing
Fair Value Inputs [Abstract]
Liabilities, Fair Value	106	105
Level 3 | Interest rate swap | Discounted cash flow
Fair Value Inputs [Abstract]
Liabilities, Fair Value	2,396	2,484
Level 3 | Collateralized debt obligations | Discounted cash flow
Fair Value Inputs [Abstract]
Assets, Fair Value	956	946
Nonrecurring | Level 3 | Impaired loans | Consensus pricing
Fair Value Inputs [Abstract]
Assets, Fair Value	9,761	20,815
Nonrecurring | Level 3 | Loan foreclosures | Consensus pricing
Fair Value Inputs [Abstract]
Assets, Fair Value	388	2,562
Nonrecurring | Level 3 | Other real estate | Consensus pricing
Fair Value Inputs [Abstract]
Assets, Fair Value	1,711	12,771