Benefit Obligations (Schedule of Company Commitments to Fund Benefit Obligations) (Details) $ in Millions		6 Months Ended
		Jun. 30, 2015 USD ($)
Multiemployer Plans, Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Total contributions year-to-date	[1]	$ 3
Total expected contributions in current fiscal year	[1]	6
Cash Contributions to Defined Benefit Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Total contributions year-to-date		27
Total expected contributions in current fiscal year		28
Other Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Total contributions year-to-date		11
Total expected contributions in current fiscal year		22
Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Total contributions year-to-date		3
Total expected contributions in current fiscal year		$ 17

[1] The Company makes contributions based on specified percentages of employee contributions.