Pension and Post-Retirement Benefits - Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Corporate stocks — common		$ 8
Government debt		8
Corporate and other non-government debt		16
Real estate	22	22
Common/collective trust funds — equity	260	223
Common/collective trust funds — government debt	18	12
Common/collective trust funds — Corporate and other non-government debt	126	88
Common/collective trust funds — real estate	1
Cash and cash equivalents	9	4
Other		5
Total	436	386
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Corporate stocks — common		8	[1]
Government debt		8	[1]
Corporate and other non-government debt		16	[1]
Real estate	0	0	[1]
Common/collective trust funds — equity	0	0	[1]
Common/collective trust funds — government debt	0	0	[1]
Common/collective trust funds — Corporate and other non-government debt	0	0	[1]
Common/collective trust funds — real estate	0
Cash and cash equivalents	5	4	[1]
Other		0	[1]
Total	5	36	[1]
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Corporate stocks — common		0	[2]
Government debt		0	[2]
Corporate and other non-government debt		0	[2]
Real estate	22	22	[2]
Common/collective trust funds — equity	260	223	[2]
Common/collective trust funds — government debt	18	12	[2]
Common/collective trust funds — Corporate and other non-government debt	126	88	[2]
Common/collective trust funds — real estate	1
Cash and cash equivalents	4	0	[2]
Other		5	[2]
Total	$ 431	$ 350	[2]

[1] Level 1 instruments use observable market prices for the identical item in active markets and have the most reliable valuations.

[2] Level 2 instruments are valued through broker/dealer quotation or through market-observable inputs for similar items in active markets. Equity securities categorized as Level 2 assets are primarily non-exchange-traded commingled or collective funds where the underlying securities have observable prices available from active markets. Valuation is based on the net asset value of fund units held as derived from the fair value of the underlying assets.