|
Marketable Securities (Narratives) (Details) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | |
|---|---|---|
|
Mar. 31, 2015
CreditRatingAgency
|
Dec. 31, 2014
|
|
| Marketable Securities | ||
| Gross unrealized losses (pre-tax) on marketable securities | $ 0 | $ 1 |
| Gross unrealized gains (pre-tax) on marketable securities | 1 | 1 |
| Percentage of asset-backed securities rated AAA/A-1+, Aaa/P-1, or AAA/F1+ | 92.20% | |
| Estimated fair value of current plus long term asset backed securities | $ 286 | |
| Number of rating agencies for which asset backed securities must be rated | 2 | |
| Number of rating agencies for asset backed securities that must be either Moody's or Standard and Poor's | 1 |