Benefit Plans (Qualified Plan Weighted-Average Asset Allocation) (Details)	Dec. 31, 2011	Dec. 31, 2010
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total investments	100.00%	100.00%
Equity Securities [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total investments	49.00%	49.00%
U.S. Treasury Securities [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total investments	17.00%	17.00%
Corporate Bonds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total investments	12.00%	14.00%
Mutual Funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total investments	11.00%	11.00%
Cash And Money Market Funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total investments	7.00%	3.00%
U.S. Government Agency Securities [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total investments	2.00%	4.00%
Trust Preferred Securities [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total investments	2.00%	2.00%