Derivative Instruments and Hedging Activities - Additional Information (Detail)
In Millions, unless otherwise specified |
1 Months Ended | 3 Months Ended | 12 Months Ended | 1 Months Ended | 12 Months Ended | 12 Months Ended | ||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2013
USD ($)
|
Dec. 31, 2012
USD ($)
|
Apr. 30, 2012
Interest Rate Swaps [Member]
Fair Value Hedge [Member]
USD ($)
|
Dec. 31, 2013
Interest Rate Swaps [Member]
Fair Value Hedge [Member]
USD ($)
|
Dec. 31, 2012
Interest Rate Swaps [Member]
Fair Value Hedge [Member]
USD ($)
|
Sep. 30, 2012
Forward Starting Interest Rate Swap [Member]
Cash Flow Hedging [Member]
USD ($)
|
Dec. 31, 2013
Forward Starting Interest Rate Swap [Member]
Cash Flow Hedging [Member]
USD ($)
|
Dec. 31, 2012
Forward Starting Interest Rate Swap [Member]
Cash Flow Hedging [Member]
USD ($)
|
Dec. 31, 2009
Forward Starting Interest Rate Swap [Member]
Cash Flow Hedging [Member]
USD ($)
|
Dec. 31, 2012
Forward Starting Interest Rate Swap [Member]
Cash Flow Hedging [Member]
Long-term other liabilities [Member]
USD ($)
|
Dec. 31, 2013
Forward Starting Interest Rate Swap [Member]
Cash Flow Hedging [Member]
Current accrued liabilities [Member]
USD ($)
|
Dec. 31, 2013
Foreign currency derivatives [Member]
Principal [Member]
October 31, 2016 [Member]
CAD
|
Oct. 31, 2013
Foreign currency derivatives [Member]
Cash Flow Hedging [Member]
USD ($)
|
Dec. 31, 2013
Foreign currency derivatives [Member]
Cash Flow Hedging [Member]
October 31, 2016 [Member]
CAD
|
Dec. 31, 2013
Foreign currency derivatives [Member]
Cash Flow Hedging [Member]
October 31, 2017 [Member]
CAD
|
Dec. 31, 2013
Foreign currency derivatives [Member]
Cash Flow Hedging [Member]
October 31, 2018 [Member]
CAD
|
Dec. 31, 2012
Foreign currency derivatives [Member]
Cash Flow Hedging [Member]
Principal [Member]
October 31, 2013 [Member]
CAD
|
Nov. 30, 2012
Foreign currency derivatives [Member]
Cash Flow Hedging [Member]
Interest [Member]
CAD
|
Nov. 30, 2011
Foreign currency derivatives [Member]
Cash Flow Hedging [Member]
Interest [Member]
CAD
|
Dec. 31, 2013
Foreign currency derivatives [Member]
Cash Flow Hedging [Member]
Interest [Member]
October 31, 2013 [Member]
CAD
|
Dec. 31, 2013
Treasury rate locks [Member]
Cash Flow Hedging [Member]
USD ($)
|
Dec. 31, 2012
Treasury rate locks [Member]
Cash Flow Hedging [Member]
USD ($)
|
Dec. 31, 2013
Electricity commodity derivatives [Member]
MW
|
Dec. 31, 2012
Electricity commodity derivatives [Member]
MW
|
Dec. 31, 2011
Electricity commodity derivatives [Member]
MW
|
Dec. 31, 2014
Electricity commodity derivatives [Member]
Forecast [Member]
MW
|
|
Derivative Instruments, Gain (Loss) [Line Items] | ||||||||||||||||||||||||||
Cash received (paid) to settle hedges | $ 76 | $ (59) | $ 4 | |||||||||||||||||||||||
Increase in carrying value of debt instruments from fair value hedge accounting for interest rate swaps | 59 | 79 | ||||||||||||||||||||||||
Notional amount | 200 | 525 | 370 | 70 | 150 | 150 | 370 | 11 | 10 | 10 | ||||||||||||||||
Maximum term of cash flow hedges | 10 years | 19 years | ||||||||||||||||||||||||
Deferred losses, net of taxes, related to cash flow hedges included in accumulated other comprehensive income | 34 | 39 | 6 | 7 | ||||||||||||||||||||||
Deferred losses scheduled to be reclassified out of accumulated other comprehensive into interest expense over next 12 months, pre-tax | 7 | 1 | ||||||||||||||||||||||||
Fair value of forward-starting swaps (interest rate derivatives) | $ 28 | $ 42 | $ 42 | $ 28 | ||||||||||||||||||||||
Merchant electricity sales hedged or expected to be hedged | 1,730,000 | 630,000 | 1,550,000 | 480,000 | ||||||||||||||||||||||
Percentage of merchant electricity sales hedged | 56.00% | 20.00% | 50.00% | |||||||||||||||||||||||
Expected percentage of merchant electricity sales hedged | 15.00% |