Fair Value Of Financial Instruments (Quantitative Information related To The Significant Unobservable Inputs Utilized In Company's Level 3 Recurring Fair Value Measurements) (Details)	12 Months Ended
	Dec. 31, 2014
State And Municipal Securities [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rate range, low end	6.30%
Discount rate range, high end	8.40%
Workout period range, low end	3 years
Workout period range, high end	4 years
Equity Securities [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rate range, low end	2.20%
Discount rate range, high end	13.20%
Workout period range, low end	1 year
Workout period range, high end	3 years
Auction Rate Municipal Securities [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rate range, low end	0.10%
Discount rate range, high end	8.60%
Workout period range, low end	1 year
Workout period range, high end	4 years
Discounted Cash Flow [Member] | State And Municipal Securities [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rate, weighted average	8.20%
Weighted average workout period	3 years 10 months 24 days
Discounted Cash Flow [Member] | Equity Securities [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rate, weighted average	5.80%
Weighted average workout period	2 years 3 months 18 days
Discounted Cash Flow [Member] | Auction Rate Municipal Securities [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rate, weighted average	7.00%
Weighted average workout period	2 years 10 months 24 days
Minimum [Member] | Partnership Interests [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Revenue multiple	1.3
EBITDA multiple	9.4
Minimum [Member] | Private Equity Investments [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Revenue multiple	0.5
EBITDA multiple	4.3
Maximum [Member] | Partnership Interests [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Revenue multiple	4.2
EBITDA multiple	15.3
Maximum [Member] | Private Equity Investments [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Revenue multiple	2.0
EBITDA multiple	9.8
Weighted Average [Member] | Market Approach [Member] | Partnership Interests [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Revenue multiple	2.9
EBITDA multiple	12.3
Weighted Average [Member] | Market Approach [Member] | Private Equity Investments [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Revenue multiple	1.4
EBITDA multiple	6.7