v2.4.0.6
Employee Benefits (Schedule Of Fair Value Of Pension Plan Assets) (Details) (USD $)
In Thousands, unless otherwise specified
 12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2011
Large-Cap Index Funds [Member]
Dec. 31, 2011
Small-Cap Index Funds [Member]
Dec. 31, 2011
International Index Funds [Member]
Dec. 31, 2011
Level 2 [Member]
Dec. 31, 2010
Level 2 [Member]
Dec. 31, 2011
Level 3 [Member]
Dec. 31, 2010
Level 3 [Member]
Dec. 31, 2011
Bank Collective Trust Funds - Equity Securities [Member]
Large-Cap Index Funds [Member]
Dec. 31, 2010
Bank Collective Trust Funds - Equity Securities [Member]
Large-Cap Index Funds [Member]
Dec. 31, 2011
Bank Collective Trust Funds - Equity Securities [Member]
Small-Cap Index Funds [Member]
Dec. 31, 2010
Bank Collective Trust Funds - Equity Securities [Member]
Small-Cap Index Funds [Member]
Dec. 31, 2011
Bank Collective Trust Funds - Equity Securities [Member]
International Index Funds [Member]
Dec. 31, 2010
Bank Collective Trust Funds - Equity Securities [Member]
International Index Funds [Member]
Dec. 31, 2011
Bank Collective Trust Funds - Equity Securities [Member]
Level 2 [Member]
Large-Cap Index Funds [Member]
Dec. 31, 2010
Bank Collective Trust Funds - Equity Securities [Member]
Level 2 [Member]
Large-Cap Index Funds [Member]
Dec. 31, 2011
Bank Collective Trust Funds - Equity Securities [Member]
Level 2 [Member]
Small-Cap Index Funds [Member]
Dec. 31, 2010
Bank Collective Trust Funds - Equity Securities [Member]
Level 2 [Member]
Small-Cap Index Funds [Member]
Dec. 31, 2011
Bank Collective Trust Funds - Equity Securities [Member]
Level 2 [Member]
International Index Funds [Member]
Dec. 31, 2010
Bank Collective Trust Funds - Equity Securities [Member]
Level 2 [Member]
International Index Funds [Member]
Dec. 31, 2010
Bank Collective Trust Funds - Equity Securities [Member]
Level 3 [Member]
Large-Cap Index Funds [Member]
Dec. 31, 2010
Bank Collective Trust Funds - Equity Securities [Member]
Level 3 [Member]
Small-Cap Index Funds [Member]
Dec. 31, 2010
Bank Collective Trust Funds - Equity Securities [Member]
Level 3 [Member]
International Index Funds [Member]
Dec. 31, 2011
Bank Collective Trust Funds - Fixed Income [Member]
Bond Index Funds [Member]
Dec. 31, 2010
Bank Collective Trust Funds - Fixed Income [Member]
Bond Index Funds [Member]
Dec. 31, 2011
Bank Collective Trust Funds - Fixed Income [Member]
Short Term Investment Funds [Member]
Dec. 31, 2010
Bank Collective Trust Funds - Fixed Income [Member]
Short Term Investment Funds [Member]
Dec. 31, 2011
Bank Collective Trust Funds - Fixed Income [Member]
Level 2 [Member]
Bond Index Funds [Member]
Dec. 31, 2010
Bank Collective Trust Funds - Fixed Income [Member]
Level 2 [Member]
Bond Index Funds [Member]
Dec. 31, 2010
Bank Collective Trust Funds - Fixed Income [Member]
Level 2 [Member]
Short Term Investment Funds [Member]
Dec. 31, 2010
Bank Collective Trust Funds - Fixed Income [Member]
Level 3 [Member]
Bond Index Funds [Member]
Dec. 31, 2011
Bank Collective Trust Funds - Fixed Income [Member]
Level 3 [Member]
Short Term Investment Funds [Member]
Dec. 31, 2010
Bank Collective Trust Funds - Fixed Income [Member]
Level 3 [Member]
Short Term Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]                                                                    
Fair value of plan assets $ 35,478 $ 32,867       $ 35,059 $ 32,400 $ 419 $ 467 $ 17,562 [1] $ 15,007 [1] $ 2,324 [2] $ 3,220 [2] $ 3,367 [3] $ 3,216 [3] $ 17,562 [1] $ 15,007 [1] $ 2,324 [2] $ 3,220 [2] $ 3,367 [3] $ 3,216 [3]    [1]    [2]    [3] $ 11,806 [4] $ 10,957 [4] $ 419 $ 467 $ 11,806 [4] $ 10,957 [4]       [4] $ 419 $ 467
Percentage of assets invested in specified company type     90.00% 95.00% 90.00%                                                          
[1] Over 90% of the assets of these funds are invested in large-cap U.S. companies. The remainder of the assets of these funds is invested in cash reserves.
[2] Over 95% of the assets of these funds are invested in small-cap U.S. companies. The remainder of the assets of these funds is invested in cash reserves.
[3] At least 90% of the assets of these funds are invested in international companies in developed markets (excluding the U.S. and Canada). The remainder of the assets of these funds is invested in cash reserves.
[4] This category represents investment grade bonds of U.S. issuers, including U.S. Treasury notes.