Employee Benefit Plans (Summary Of Fair Value Of Pension Plan Assets) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	$ 1,701,694	$ 1,438,865
Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1,701,694	1,438,865	1,281,261
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	460,982	443,971
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1,240,712	901,118
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	93,776	87,060
Hedge Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	53,364	50,149
Private Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	40,412	36,911
Short-Term Investment Fund [Member] | Cash And Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	48,296	65,100
Short-Term Investment Fund [Member] | Fair Value, Inputs, Level 1 [Member] | Cash And Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Short-Term Investment Fund [Member] | Fair Value, Inputs, Level 2 [Member] | Cash And Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	48,296	65,100
Short-Term Investment Fund [Member] | Fair Value, Inputs, Level 3 [Member] | Cash And Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Long-term Debt [Member] | Fixed-Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1,252,077	832,915
Long-term Debt [Member] | Fair Value, Inputs, Level 1 [Member] | Fixed-Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	131,997	91,824
Long-term Debt [Member] | Fair Value, Inputs, Level 2 [Member] | Fixed-Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1,120,080	741,091
Long-term Debt [Member] | Fair Value, Inputs, Level 3 [Member] | Fixed-Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Hedge Funds, Multi-strategy [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets		53,364
Hedge Funds, Multi-strategy [Member] | Fair Value, Inputs, Level 1 [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets		0
Hedge Funds, Multi-strategy [Member] | Fair Value, Inputs, Level 2 [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets		0
Hedge Funds, Multi-strategy [Member] | Fair Value, Inputs, Level 3 [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets		53,364
Real Estate Investment Trust Index Fund [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets		40,412
Real Estate Investment Trust Index Fund [Member] | Fair Value, Inputs, Level 1 [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets		0
Real Estate Investment Trust Index Fund [Member] | Fair Value, Inputs, Level 2 [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets		0
Real Estate Investment Trust Index Fund [Member] | Fair Value, Inputs, Level 3 [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets		40,412
U S Large Companies [Member] | S&P 500 Index Fund [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	2,309	3,482
U S Large Companies [Member] | S&P 500 Index Fund [Member] | Fair Value, Inputs, Level 1 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	2,309	3,482
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]
Fair value of pension plan assets	0	0
U S Large Companies [Member] | S&P 500 Index Fund [Member] | Fair Value, Inputs, Level 3 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
U S Large Companies [Member] | Growth [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	102,653	99,050
U S Large Companies [Member] | Growth [Member] | Fair Value, Inputs, Level 1 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	102,653	99,050
U S Large Companies [Member] | Growth [Member] | Fair Value, Inputs, Level 2 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
U S Large Companies [Member] | Growth [Member] | Fair Value, Inputs, Level 3 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
U S Large Companies [Member] | Value [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	99,466	101,154
U S Large Companies [Member] | Value [Member] | Fair Value, Inputs, Level 1 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	99,466	101,154
U S Large Companies [Member] | Value [Member] | Fair Value, Inputs, Level 2 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
U S Large Companies [Member] | Value [Member] | Fair Value, Inputs, Level 3 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
U S Small Companies [Member] | Value [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	32,298	57,403
U S Small Companies [Member] | Value [Member] | Fair Value, Inputs, Level 1 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	32,298	57,403
U S Small Companies [Member] | Value [Member] | Fair Value, Inputs, Level 2 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
U S Small Companies [Member] | Value [Member] | Fair Value, Inputs, Level 3 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
International | Growth [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	92,259	91,058
International | Growth [Member] | Fair Value, Inputs, Level 1 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	92,259	91,058
International | Growth [Member] | Fair Value, Inputs, Level 2 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
International | Growth [Member] | Fair Value, Inputs, Level 3 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
International | Value [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	72,336	94,927
International | Value [Member] | Fair Value, Inputs, Level 1 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
International | Value [Member] | Fair Value, Inputs, Level 2 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	72,336	94,927
International | Value [Member] | Fair Value, Inputs, Level 3 [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	$ 0	$ 0