Employee Benefit Plans (Summary Of Fair Value Of Pension Plan Assets) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 1,281,261	$ 1,105,370
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	479,953	557,755
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	714,248	513,095
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	87,060	34,520	29,553
Short-Term Investment Fund [Member] | Cash And Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	33,569	52,076
Short-Term Investment Fund [Member] | Fair Value, Inputs, Level 2 [Member] | Cash And Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	33,569	52,076
Long-term Debt [Member] | Fixed-Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	511,990	287,828
Long-term Debt [Member] | Fair Value, Inputs, Level 1 [Member] | Fixed-Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	52,524	42,663
Long-term Debt [Member] | Fair Value, Inputs, Level 2 [Member] | Fixed-Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	459,466	245,165
Low-Duration Fund [Member] | Fixed-Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		72,066
Low-Duration Fund [Member] | Fair Value, Inputs, Level 1 [Member] | Fixed-Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		72,066
Private Fund [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	36,911	34,520	29,553
Private Fund [Member] | Fair Value, Inputs, Level 3 [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	36,911	34,520
Real Estate Investment Trust Index Fund [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	22,966	19,608
Real Estate Investment Trust Index Fund [Member] | Fair Value, Inputs, Level 2 [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	22,966	19,608
Hedge Funds, Multi-strategy [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	50,149
Hedge Funds, Multi-strategy [Member] | Fair Value, Inputs, Level 3 [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	50,149
U S Large Companies [Member] | S&P 500 Index Fund [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	105,523	116,391
U S Large Companies [Member] | S&P 500 Index Fund [Member] | Fair Value, Inputs, Level 2 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	105,523	116,391
U S Large Companies [Member] | Growth [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	96,409	133,556
U S Large Companies [Member] | Growth [Member] | Fair Value, Inputs, Level 1 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	96,409	133,556
U S Large Companies [Member] | Value [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	146,501	138,241
U S Large Companies [Member] | Value [Member] | Fair Value, Inputs, Level 1 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	146,501	138,241
U S Small Companies [Member] | Growth [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	41,720	36,483
U S Small Companies [Member] | Growth [Member] | Fair Value, Inputs, Level 1 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	41,720	36,483
U S Small Companies [Member] | Value [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	58,126	64,764
U S Small Companies [Member] | Value [Member] | Fair Value, Inputs, Level 1 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	58,126	64,764
International | Growth [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	84,673	69,982
International | Growth [Member] | Fair Value, Inputs, Level 1 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	84,673	69,982
International | Value [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	92,724	79,855
International | Value [Member] | Fair Value, Inputs, Level 2 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 92,724	$ 79,855