Fair Value Measurements Fair Value Measurements, Financial Instruments Measured On a Recurring Basis, Quantitative Information (Details) (Fair Value, Inputs, Level 3 [Member], USD $) In Thousands, unless otherwise specified	9 Months Ended				12 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Dec. 31, 2012
Available-for-sale Securities [Member] | Municipal and other tax-exempt securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Asset, Par Value	$ 45,470		$ 46,100		$ 45,570
Fair Value Inputs, Asset, Amortized Cost	39,391	[1]	42,395	[1]	40,857	[1]
Fair Value Inputs, Asset, Fair Value	39,671		41,279		40,702
Available-for-sale Securities [Member] | Municipal and other tax-exempt securities [Member] | External Credit Rating, Investment Grade [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Asset, Par Value	21,545		29,100		28,570
Fair Value Inputs, Asset, Amortized Cost	21,467	[1]	28,999	[1]	28,473	[1]
Fair Value Inputs, Asset, Fair Value	20,531		28,848		28,318
Fair Value Measurements, Valuation Techniques	Discounted cash flows	[2]	Discounted cash flows	[2]	Discounted cash flows	[2]
Fair Value Measurements, Significant Unobservable Input	Interest rate spread		Interest rate spread		Interest rate spread
Fair Value Inputs, Assets, Discount Rate, Minimum	4.98%	[3]	1.00%	[4]	1.00%	[4]
Fair Value Inputs, Assets, Discount Rate, Maximum	5.28%	[3]	1.50%	[4]	1.50%	[4]
Fair Value Inputs, Assets, Discount Rate, Weighted Average	5.15%	[3]	1.25%	[4]	1.25%	[4]
Fair Value Inputs, Assets, Fair Value As Percentage of Par Value, Minimum	95.02%	[5]	98.85%	[5]	98.83%	[5]
Fair Value Inputs, Assets, Fair Value As Percentage of Par Value, Maximum	95.55%	[5]	99.47%	[5]	99.43%	[5]
Fair Value Inputs, Fair Value As Percentage of Par Value, Weighted Average	95.29%	[5]	99.13%	[5]	99.12%	[5]
Investment Grade Tax Exempt Securities Yield Spread Over Comparable Securities Minimum	462		75		75
Investment Grade Tax Exempt Securities Yield Spread Over Comparable Securities Maximum	517		80		80
Additional Decrease in Fair Value From a 100 Basis Point Increase in Interest Rate Spread	(199)
Available-for-sale Securities [Member] | Municipal and other tax-exempt securities [Member] | External Credit Rating, Non Investment Grade [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Asset, Par Value	23,925		17,000		17,000
Fair Value Inputs, Asset, Amortized Cost	17,924	[1]	13,396	[1]	12,384	[1]
Fair Value Inputs, Asset, Fair Value	19,140		12,431		12,384
Fair Value Measurements, Valuation Techniques	Proposed settlement agreement	[6]	Discounted cash flows	[2]	Discounted cash flows	[2]
Fair Value Measurements, Significant Unobservable Input	Discount for settlement uncertainty		Interest rate spread		Interest rate spread
Fair Value Inputs, Assets, Discount Rate, Minimum			7.20%	[7]	7.21%	[7]
Fair Value Inputs, Assets, Discount Rate, Maximum			9.88%	[7]	9.83%	[7]
Fair Value Inputs, Assets, Discount Rate, Weighted Average			7.77%	[7]	7.82%	[7]
Fair Value Inputs, Assets, Fair Value As Percentage of Par Value, Minimum	80.00%	[5]	73.06%	[5]	72.79%	[5]
Fair Value Inputs, Assets, Fair Value As Percentage of Par Value, Maximum	80.00%	[5]	73.30%	[5]	73.00%	[5]
Fair Value Inputs, Fair Value As Percentage of Par Value, Weighted Average	80.00%	[5]	73.13%	[5]	72.85%	[5]
Below Investment Grade Tax Exempt Securities Yield Spread Over Comparable Securities			700		700
Available-for-sale Securities [Member] | Other debt securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Asset, Par Value	4,900		5,400		5,400
Fair Value Inputs, Asset, Amortized Cost	4,900	[1]	5,400	[1]	5,400	[1]
Fair Value Inputs, Asset, Fair Value	4,712		5,400		5,399
Fair Value Measurements, Valuation Techniques	Discounted cash flows	[2]	Discounted cash flows	[2]	Discounted cash flows	[2]
Fair Value Measurements, Significant Unobservable Input	Interest rate spread		Interest rate spread		Interest rate spread
Fair Value Inputs, Assets, Discount Rate, Minimum	5.60%	[8]	1.70%	[8]	1.65%	[8]
Fair Value Inputs, Assets, Discount Rate, Maximum	5.68%	[8]	1.73%	[8]	1.71%	[8]
Fair Value Inputs, Assets, Discount Rate, Weighted Average	5.67%	[8]	1.71%	[8]	1.70%	[8]
Fair Value Inputs, Assets, Fair Value As Percentage of Par Value, Minimum	96.16%	[5]	100.00%	[5]	100.00%	[5]
Fair Value Inputs, Assets, Fair Value As Percentage of Par Value, Maximum	96.16%	[5]	100.00%	[5]	100.00%	[5]
Fair Value Inputs, Fair Value As Percentage of Par Value, Weighted Average	96.16%	[5]	100.00%	[5]	100.00%	[5]
Average Yields On Comparable Short-term Taxable Securities Maximum	1.00%		1.00%		1.00%
Additional Decrease in Fair Value From a 100 Basis Point Increase in Interest Rate Spread	(45)
Available-for-sale Securities [Member] | Equity securities and mutual funds [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Asset, Amortized Cost	2,420	[1]			2,161	[1]
Fair Value Inputs, Asset, Fair Value	4,207				2,161
Fair Value Measurements, Valuation Techniques	Publicly announced preliminary purchase price information from acquirer.				Tangible book value per share of publicly traded financial institutions of similar size, less liquidity discount.	[9]
Fair Value Measurements, Significant Unobservable Input	Discount for settlement uncertainty				Peer group tangible book per share and liquidity discount.
Fair Value Inputs, Assets, Liquidity Discount					20.00%
Other assets - private equity funds [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Asset, Fair Value	$ 27,799		$ 28,792		$ 28,169
Fair Value Measurements, Valuation Techniques	Net asset value reported by underlying fund		Net asset value reported by underlying fund		Net asset value reported by underlying fund
Fair Value Measurements, Significant Unobservable Input	Net asset value reported by underlying fund		Net asset value reported by underlying fund		Net asset value reported by underlying fund

[1] Amortized cost reduced by other-than-temporary impairments recorded in earnings. See Note 2 for additional discussion.

[2] Discounted cash flows developed using discount rates primarily based on reference to interest rate spreads for comparable securities of similar duration and credit rating as determined by the nationally-recognized rating agencies, adjusted for lack of trading volume

[3] Interest rate yields used to value investment grade tax-exempt securities represent a spread of 462 to 517 basis points over average yields for comparable tax-exempt securities.

[4] Interest rate yields used to value investment grade tax-exempt securities represent a spread of 75 to 80 basis points over average yields for comparable tax-exempt securities.

[5] Represents fair value as a percentage of par value

[6]

[7] Interest rate yields determined using a spread of 700 basis points over comparable municipal securities of varying durations.

[8] Interest rate yields used to value investment grade taxable securities based on comparable short-term taxable securities which are generally yielding less than 1%.

[9] Fair value of shares of a smaller privately-held financial institution were valued using the tangible book value per share of similarly sized financial institutions within the immediate geographical market with a discount of 20% due to the liquidity of the shares.