Employee Benefits (Schedule Of Fair Value Of Pension Plan Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 486	$ 650
Domestic Plan [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	223	264
Domestic Plan [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	263	386
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	17	18
Foreign Plan [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5	5
Foreign Plan [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12	13
Cash and Cash Equivalents [Member] | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and Cash Equivalents [Member] | Domestic Plan [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and Cash Equivalents [Member] | Domestic Plan [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and Cash Equivalents [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5	5
Cash and Cash Equivalents [Member] | Foreign Plan [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5	5
Cash and Cash Equivalents [Member] | Foreign Plan [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Common Stock [Member] | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	13	21
Common Stock [Member] | Domestic Plan [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	13	21
Common Stock [Member] | Domestic Plan [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Common Stock [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Common Stock [Member] | Foreign Plan [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Common Stock [Member] | Foreign Plan [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Large-Cap Mutual Funds [Member] | Domestic Plan [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	142	222
Large-Cap Mutual Funds [Member] | Domestic Plan [Member] | Level 1 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	44	49
Large-Cap Mutual Funds [Member] | Domestic Plan [Member] | Level 2 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	98	173
Large-Cap Mutual Funds [Member] | Foreign Plan [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1	2
Large-Cap Mutual Funds [Member] | Foreign Plan [Member] | Level 1 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Large-Cap Mutual Funds [Member] | Foreign Plan [Member] | Level 2 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1	2
Small-Cap Mutual Funds [Member] | Domestic Plan [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	19	34
Small-Cap Mutual Funds [Member] | Domestic Plan [Member] | Level 1 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6	9
Small-Cap Mutual Funds [Member] | Domestic Plan [Member] | Level 2 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	13	25
Small-Cap Mutual Funds [Member] | Foreign Plan [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Small-Cap Mutual Funds [Member] | Foreign Plan [Member] | Level 1 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Small-Cap Mutual Funds [Member] | Foreign Plan [Member] | Level 2 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
International Mutual Funds [Member] | Domestic Plan [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	102	119
International Mutual Funds [Member] | Domestic Plan [Member] | Level 1 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	64	69
International Mutual Funds [Member] | Domestic Plan [Member] | Level 2 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	38	50
International Mutual Funds [Member] | Foreign Plan [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5	5
International Mutual Funds [Member] | Foreign Plan [Member] | Level 1 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
International Mutual Funds [Member] | Foreign Plan [Member] | Level 2 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5	5
Bond Mutual Funds [Member] | Domestic Plan [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	198	241
Bond Mutual Funds [Member] | Domestic Plan [Member] | Level 1 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	96	116
Bond Mutual Funds [Member] | Domestic Plan [Member] | Level 2 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	102	125
Bond Mutual Funds [Member] | Foreign Plan [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6	6
Bond Mutual Funds [Member] | Foreign Plan [Member] | Level 1 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Bond Mutual Funds [Member] | Foreign Plan [Member] | Level 2 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6	6
Short Term Investment Funds [Member] | Domestic Plan [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12	13
Short Term Investment Funds [Member] | Domestic Plan [Member] | Level 1 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Short Term Investment Funds [Member] | Domestic Plan [Member] | Level 2 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12	13
Short Term Investment Funds [Member] | Foreign Plan [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Short Term Investment Funds [Member] | Foreign Plan [Member] | Level 1 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Short Term Investment Funds [Member] | Foreign Plan [Member] | Level 2 [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	$ 0