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	3 Months Ended				12 Months Ended
	Mar. 31, 2014		Mar. 31, 2013		Dec. 31, 2012		Dec. 31, 2013
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	$ 16,295		$ 45,470				$ 18,695
Fair Value Inputs, Asset, Amortized Cost	16,224		40,758	[1]			18,624
Fair Value Inputs, Asset, Fair Value	15,523		39,007				17,805
Fair Value Measurements, Valuation Techniques	Discounted cash flows	[2]			Discounted cash flows	[2]
Fair Value Measurements, Significant Unobservable Input	Interest rate spread				Interest rate spread
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			28,470
Fair Value Inputs, Asset, Amortized Cost			28,374	[1]
Fair Value Inputs, Asset, Fair Value			27,120
Fair Value Measurements, Valuation Techniques			Discounted cash flows	[2]
Fair Value Measurements, Significant Unobservable Input			Interest rate spread
Fair Value Inputs, Assets, Discount Rate, Minimum	4.95%	[3]	5.00%	[4]			4.97%	[5]
Fair Value Inputs, Assets, Discount Rate, Maximum	5.25%	[3]	5.50%	[4]			5.27%	[5]
Fair Value Inputs, Assets, Discount Rate, Weighted Average	5.13%	[3]	5.25%	[4]			5.16%	[5]
Fair Value Inputs, Assets, Fair Value As Percentage of Par Value, Minimum	95.05%	[6]	95.01%	[6]			95.02%	[6]
Fair Value Inputs, Assets, Fair Value As Percentage of Par Value, Maximum	95.49%	[6]	95.59%	[6]			95.50%	[6]
Fair Value Inputs, Fair Value As Percentage of Par Value, Weighted Average	95.26%	[6]	95.26%	[6]			95.24%	[6]
Investment Grade Tax Exempt Securities Yield Spread Over Comparable Securities Minimum	468		458				467
Investment Grade Tax Exempt Securities Yield Spread Over Comparable Securities Maximum	515		519				518
Additional Decrease in Fair Value From a 100 Basis Point Increase in Interest Rate Spread	(150)
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			17,000
Fair Value Inputs, Asset, Amortized Cost			12,384	[1]
Fair Value Inputs, Asset, Fair Value			11,887
Fair Value Measurements, Valuation Techniques			Discounted cash flows	[2]
Fair Value Measurements, Significant Unobservable Input			Interest rate spread
Fair Value Inputs, Assets, Discount Rate, Minimum			8.80%	[7]
Fair Value Inputs, Assets, Discount Rate, Maximum			11.20%	[7]
Fair Value Inputs, Assets, Discount Rate, Weighted Average			9.54%	[7]
Fair Value Inputs, Assets, Fair Value As Percentage of Par Value, Minimum			69.86%	[6]
Fair Value Inputs, Assets, Fair Value As Percentage of Par Value, Maximum			70.04%	[6]
Fair Value Inputs, Fair Value As Percentage of Par Value, Weighted Average			69.92%	[6]
Below Investment Grade Tax Exempt Securities Yield Spread Over Comparable Securities			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				4,900
Fair Value Inputs, Asset, Amortized Cost	4,900		5,400	[1]			4,900
Fair Value Inputs, Asset, Fair Value	4,712		5,193				4,712
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	5.46%	[8]	5.44%	[8]			5.67%	[9]
Fair Value Inputs, Assets, Discount Rate, Maximum	5.66%	[8]	5.71%	[8]			5.67%	[9]
Fair Value Inputs, Assets, Discount Rate, Weighted Average	5.63%	[8]	5.68%	[8]			5.67%	[9]
Fair Value Inputs, Assets, Fair Value As Percentage of Par Value, Minimum	96.16%	[6]	96.16%	[6]			96.16%	[6]
Fair Value Inputs, Assets, Fair Value As Percentage of Par Value, Maximum	96.16%	[6]	96.16%	[6]			96.16%	[6]
Fair Value Inputs, Fair Value As Percentage of Par Value, Weighted Average	96.16%	[6]	96.16%	[6]			96.16%	[6]
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				2,420
Fair Value Inputs, Asset, Fair Value			2,472				4,207
Fair Value Measurements, Valuation Techniques			Tangible book value per share of publicly traded financial institutions of similar size, less liquidity discount.		Publicly announced preliminary purchase price information from acquirer.
Fair Value Measurements, Significant Unobservable Input			Peer group tangible book per share and liquidity discount.		Discount for settlement uncertainty.
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	$ 27,466		$ 29,216				$ 27,341
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 468 to 515 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 458 to 519 basis points over average yields for comparable tax-exempt securities.

[5] Interest rate yields used to value investment grade tax-exempt securities represent a spread of 467 to 518 basis points over average yields for comparable tax-exempt securities.

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

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