Derivatives and Risk Management Activities (Details 3) In Millions, unless otherwise specified	Dec. 31, 2013 Foreign exchange contracts CAD	Dec. 31, 2013 Foreign Exchange Forward Contracts that exchange CAD for USD at the Rate USD 1.00 to CAD 1.06 Maturing in 2014 USD ($)	Dec. 31, 2013 Foreign Exchange Forward Contracts that exchange CAD for USD at the Rate USD 1.00 to CAD 1.06 Maturing in 2014 CAD	Dec. 31, 2013 Foreign Exchange Forward Contracts that exchange CAD for USD at the Rate USD 1.00 to CAD 1.07 Maturing in 2015 USD ($)	Dec. 31, 2013 Foreign Exchange Forward Contracts that exchange CAD for USD at the Rate USD 1.00 to CAD 1.07 Maturing in 2015 CAD	Dec. 31, 2013 Foreign Exchange Forward Contracts that exchange CAD for USD at the Rate USD 1.00 to CAD 1.06 USD ($)	Dec. 31, 2013 Foreign Exchange Forward Contracts that exchange CAD for USD at the Rate USD 1.00 to CAD 1.06 CAD	Dec. 31, 2013 Foreign Exchange Forward Contracts that exchange USD for CAD at the Rate USD 1.00 to CAD 1.05 Maturing in 2014 USD ($)	Dec. 31, 2013 Foreign Exchange Forward Contracts that exchange USD for CAD at the Rate USD 1.00 to CAD 1.05 Maturing in 2014 CAD	Dec. 31, 2013 Foreign Exchange Forward Contracts that exchange USD for CAD at the Rate USD 1.00 to CAD 1.06 Maturing in 2015 USD ($)	Dec. 31, 2013 Foreign Exchange Forward Contracts that exchange USD for CAD at the Rate USD 1.00 to CAD 1.06 Maturing in 2015 CAD	Dec. 31, 2013 Foreign Exchange Forward Contracts that exchange USD for CAD at the Rate USD 1.00 to CAD 1.05 USD ($)	Dec. 31, 2013 Foreign Exchange Forward Contracts that exchange USD for CAD at the Rate USD 1.00 to CAD 1.05 CAD	Dec. 31, 2013 Foreign Exchange Forward Contracts Maturing in 2014 CAD
Currency Exchange Rate Risk Hedging:
Notional amount of derivatives	4	$ 336	358	$ 9	9	$ 345	367	$ 336	354	$ 9	9	$ 345	363	4
Average exchange rate for outstanding foreign currency forward exchange contracts			1.06		1.07		1.06		1.05		1.06		1.05