Retirement, Other Postretirement Benefits, And Defined Contribution Plans (Investments Held For Qualified Pension And Other Postretirement Plans Measured At Fair Value) (Details) - USD ($) $ in Thousands		Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		$ 4,744,032		$ 4,855,066
Cash		373		495
Other pending transactions		1,124		7,359
Less: Other postretirement assets included in total investments		(38,096)		(34,954)
Total fair value of qualified pension assets		4,707,433		4,827,966
Qualified Pension Plans [Member] | Preferred [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		6,409		10,017
Qualified Pension Plans [Member] | Common Stock [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		686,430		717,782
Qualified Pension Plans [Member] | Common Collective Trusts [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		1,873,218		1,886,897
Qualified Pension Plans [Member] | 103-12 Investment Entities [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		283,288		259,995
Qualified Pension Plans [Member] | U.S. Government securities [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		345,684		400,299
Qualified Pension Plans [Member] | Corporate Debt Securities [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		595,862		548,788
Qualified Pension Plans [Member] | Registered Investment Companies [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		802,928		863,175
Qualified Pension Plans [Member] | Other [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		114,215		130,295
Qualified Pension Plans [Member] | Insurance Company General Account (Unallocated Contracts) [Member] | Other Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		35,998		37,818
Other Postretirement [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		540,493		562,508
Other pending transactions		480		165
Plus: Other postretirement assets included in the investments of the qualified pension trust		38,096		34,954
Total fair value of qualified pension assets		579,069		597,627		$ 569,850
Other Postretirement [Member] | Common Collective Trusts [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		348,604		370,228
Other Postretirement [Member] | U.S. Government securities [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		76,011		81,924
Other Postretirement [Member] | Corporate Debt Securities [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		62,629		57,830
Other Postretirement [Member] | Registered Investment Companies [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		3,572		5,558
Other Postretirement [Member] | Other [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		49,677		46,968
Fair Value Inputs Level 1 [Member] | Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		950,343		1,014,476
Fair Value Inputs Level 1 [Member] | Qualified Pension Plans [Member] | Preferred [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[1]	6,409		10,017
Fair Value Inputs Level 1 [Member] | Qualified Pension Plans [Member] | Common Stock [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[1]	686,335		717,685
Fair Value Inputs Level 1 [Member] | Qualified Pension Plans [Member] | Common Collective Trusts [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[2]	0		0
Fair Value Inputs Level 1 [Member] | Qualified Pension Plans [Member] | 103-12 Investment Entities [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[3]	0		0
Fair Value Inputs Level 1 [Member] | Qualified Pension Plans [Member] | U.S. Government securities [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		1,879	[1]	240	[4]
Fair Value Inputs Level 1 [Member] | Qualified Pension Plans [Member] | Corporate Debt Securities [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[4]	0		0
Fair Value Inputs Level 1 [Member] | Qualified Pension Plans [Member] | Registered Investment Companies [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		255,720	[5]	286,534	[6]
Fair Value Inputs Level 1 [Member] | Qualified Pension Plans [Member] | Other [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[7]	0		0
Fair Value Inputs Level 1 [Member] | Qualified Pension Plans [Member] | Insurance Company General Account (Unallocated Contracts) [Member] | Other Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[8]	0		0
Fair Value Inputs Level 1 [Member] | Other Postretirement [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		37,361		41,864
Fair Value Inputs Level 1 [Member] | Other Postretirement [Member] | Common Collective Trusts [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[2]	0		0
Fair Value Inputs Level 1 [Member] | Other Postretirement [Member] | U.S. Government securities [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[1]	33,789		36,306
Fair Value Inputs Level 1 [Member] | Other Postretirement [Member] | Corporate Debt Securities [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[4]	0		0
Fair Value Inputs Level 1 [Member] | Other Postretirement [Member] | Registered Investment Companies [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[5]	3,572		5,558
Fair Value Inputs Level 1 [Member] | Other Postretirement [Member] | Other [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[7]	0		0
Fair Value Inputs Level 2 [Member] | Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		3,793,689		3,840,590
Fair Value Inputs Level 2 [Member] | Qualified Pension Plans [Member] | Preferred [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[4]	0		0
Fair Value Inputs Level 2 [Member] | Qualified Pension Plans [Member] | Common Stock [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		95		97
Fair Value Inputs Level 2 [Member] | Qualified Pension Plans [Member] | Common Collective Trusts [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[2]	1,873,218		1,886,897
Fair Value Inputs Level 2 [Member] | Qualified Pension Plans [Member] | 103-12 Investment Entities [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[3]	283,288		259,995
Fair Value Inputs Level 2 [Member] | Qualified Pension Plans [Member] | U.S. Government securities [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[4]	343,805		400,059
Fair Value Inputs Level 2 [Member] | Qualified Pension Plans [Member] | Corporate Debt Securities [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[4]	595,862		548,788
Fair Value Inputs Level 2 [Member] | Qualified Pension Plans [Member] | Registered Investment Companies [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[6]	547,208		576,641
Fair Value Inputs Level 2 [Member] | Qualified Pension Plans [Member] | Other [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[7]	114,215		130,295
Fair Value Inputs Level 2 [Member] | Qualified Pension Plans [Member] | Insurance Company General Account (Unallocated Contracts) [Member] | Other Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[8]	35,998		37,818
Fair Value Inputs Level 2 [Member] | Other Postretirement [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		503,132		520,644
Fair Value Inputs Level 2 [Member] | Other Postretirement [Member] | Common Collective Trusts [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[2]	348,604		370,228
Fair Value Inputs Level 2 [Member] | Other Postretirement [Member] | U.S. Government securities [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[4]	42,222		45,618
Fair Value Inputs Level 2 [Member] | Other Postretirement [Member] | Corporate Debt Securities [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[4]	62,629		57,830
Fair Value Inputs Level 2 [Member] | Other Postretirement [Member] | Registered Investment Companies [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[5]	0		0
Fair Value Inputs Level 2 [Member] | Other Postretirement [Member] | Other [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[7]	49,677		46,968
Fair Value Inputs Level 3 [Member] | Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		0		0
Fair Value Inputs Level 3 [Member] | Qualified Pension Plans [Member] | Preferred [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[4]	0		0
Fair Value Inputs Level 3 [Member] | Qualified Pension Plans [Member] | Common Stock [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		0
Fair Value Inputs Level 3 [Member] | Qualified Pension Plans [Member] | Common Collective Trusts [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[2]	0		0
Fair Value Inputs Level 3 [Member] | Qualified Pension Plans [Member] | 103-12 Investment Entities [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[3]	0		0
Fair Value Inputs Level 3 [Member] | Qualified Pension Plans [Member] | U.S. Government securities [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[4]	0		0
Fair Value Inputs Level 3 [Member] | Qualified Pension Plans [Member] | Corporate Debt Securities [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[4]	0		0
Fair Value Inputs Level 3 [Member] | Qualified Pension Plans [Member] | Registered Investment Companies [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[6]	0		0
Fair Value Inputs Level 3 [Member] | Qualified Pension Plans [Member] | Other [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[7]	0		0
Fair Value Inputs Level 3 [Member] | Qualified Pension Plans [Member] | Insurance Company General Account (Unallocated Contracts) [Member] | Other Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[8]	0		0
Fair Value Inputs Level 3 [Member] | Other Postretirement [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments		0		0
Fair Value Inputs Level 3 [Member] | Other Postretirement [Member] | Common Collective Trusts [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[2]	0		0
Fair Value Inputs Level 3 [Member] | Other Postretirement [Member] | U.S. Government securities [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[4]	0		0
Fair Value Inputs Level 3 [Member] | Other Postretirement [Member] | Corporate Debt Securities [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[4]	0		0
Fair Value Inputs Level 3 [Member] | Other Postretirement [Member] | Registered Investment Companies [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[5]	0		0
Fair Value Inputs Level 3 [Member] | Other Postretirement [Member] | Other [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments	[7]	$ 0		$ 0

[1] (b)Common stocks, certain preferred stocks, and certain fixed income debt securities (government) are stated at fair value determined by quoted market prices.

[2] (c)The common collective trusts hold investments in accordance with stated objectives. The investment strategy of the trusts is to capture the growth potential of equity markets by replicating the performance of a specified index.

[3] (h)103-12 investment entities hold investments in accordance with stated objectives. The investment strategy of the investment entities is to capture the growth potential of international equity markets by replicating the performance of a specified index. Net asset value per share of the 103-12 investment entities estimate fair value.

[4] (a)Certain preferred stocks and certain fixed income debt securities (corporate, government, and securitized) are stated at fair value as determined by broker quotes.

[5] (d)The registered investment company is a money market mutual fund with a stable net asset value of one dollar per share.

[6] (e)The registered investment company holds investments in domestic and international bond markets and estimates fair value using net asset value per share.

[7] (f)The other remaining assets are U.S. municipal and foreign government bonds stated at fair value as determined by broker quotes.

[8] (g)The unallocated insurance contract investments are recorded at contract value, which approximates fair value. The contract value represents contributions made under the contract, plus interest, less funds used to pay benefits and contract expenses, and less distributions to the master trust.