Fair Value Measurements, Derivative Instruments and Hedging Activities - Fuel Derivatives Outstanding (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Feb. 28, 2015	Feb. 28, 2014
Fuel Derivatives 2015 Maturity
Derivative [Line Items]
Barrels	7,803,000
Percent of Estimated Fuel Consumption	50.00%
Fuel Derivatives 2015 Maturity November 2011 Transaction Date
Derivative [Line Items]
Barrels	1,620,000
Weighted-Average Floor Price (in dollars per barrel)	80
Weighted-Average Ceiling Price (in dollars per barrel)	114
Fuel Derivatives 2015 Maturity February 2012 Transaction Date
Derivative [Line Items]
Barrels	1,620,000
Weighted-Average Floor Price (in dollars per barrel)	80
Weighted-Average Ceiling Price (in dollars per barrel)	125
Fuel Derivatives 2015 Maturity June 2012 Transaction Date
Derivative [Line Items]
Barrels	927,000
Weighted-Average Floor Price (in dollars per barrel)	74
Weighted-Average Ceiling Price (in dollars per barrel)	110
Fuel Derivatives 2015 Maturity April 2013 Transaction Date
Derivative [Line Items]
Barrels	783,000
Weighted-Average Floor Price (in dollars per barrel)	80
Weighted-Average Ceiling Price (in dollars per barrel)	111
Fuel Derivatives 2015 Maturity May 2013 Transaction Date
Derivative [Line Items]
Barrels	1,413,000
Weighted-Average Floor Price (in dollars per barrel)	80
Weighted-Average Ceiling Price (in dollars per barrel)	110
Fuel Derivatives 2015 Maturity October 2014 Transaction Date
Derivative [Line Items]
Barrels	1,440,000
Weighted-Average Floor Price (in dollars per barrel)	79
Weighted-Average Ceiling Price (in dollars per barrel)	110
Fuel Derivatives 2016 Maturity
Derivative [Line Items]
Barrels	8,724,000
Percent of Estimated Fuel Consumption	44.00%
Fuel Derivatives 2016 Maturity June 2012 Transaction Date
Derivative [Line Items]
Barrels	3,564,000
Weighted-Average Floor Price (in dollars per barrel)	75
Weighted-Average Ceiling Price (in dollars per barrel)	108
Fuel Derivatives 2016 Maturity February 2013 Transaction Date
Derivative [Line Items]
Barrels	2,160,000
Weighted-Average Floor Price (in dollars per barrel)	80
Weighted-Average Ceiling Price (in dollars per barrel)	120
Fuel Derivatives 2016 Maturity April 2013 Transaction Date
Derivative [Line Items]
Barrels	3,000,000
Weighted-Average Floor Price (in dollars per barrel)	75
Weighted-Average Ceiling Price (in dollars per barrel)	115
Fuel Derivatives 2017 Maturity
Derivative [Line Items]
Barrels	8,124,000
Percent of Estimated Fuel Consumption	41.00%
Fuel Derivatives 2017 Maturity February 2013 Transaction Date
Derivative [Line Items]
Barrels	3,276,000
Weighted-Average Floor Price (in dollars per barrel)	80
Weighted-Average Ceiling Price (in dollars per barrel)	115
Fuel Derivatives 2017 Maturity April 2013 Transaction Date
Derivative [Line Items]
Barrels	2,028,000
Weighted-Average Floor Price (in dollars per barrel)	75
Weighted-Average Ceiling Price (in dollars per barrel)	110
Fuel Derivatives 2017 Maturity January 2014 Transaction Date
Derivative [Line Items]
Barrels	1,800,000
Weighted-Average Floor Price (in dollars per barrel)	75
Weighted-Average Ceiling Price (in dollars per barrel)	114
Fuel Derivatives 2017 Maturity October 2014 Transaction Date
Derivative [Line Items]
Barrels	1,020,000
Weighted-Average Floor Price (in dollars per barrel)	80
Weighted-Average Ceiling Price (in dollars per barrel)	113
Fuel Derivatives 2018 Maturity
Derivative [Line Items]
Barrels	5,700,000
Percent of Estimated Fuel Consumption	29.00%
Fuel Derivatives 2018 Maturity January 2014 Transaction Date
Derivative [Line Items]
Barrels	2,700,000
Weighted-Average Floor Price (in dollars per barrel)	75
Weighted-Average Ceiling Price (in dollars per barrel)	110
Fuel Derivatives 2018 Maturity October 2014 Transaction Date
Derivative [Line Items]
Barrels	3,000,000
Weighted-Average Floor Price (in dollars per barrel)	80
Weighted-Average Ceiling Price (in dollars per barrel)	114
Fuel
Derivative [Line Items]
Unrealized gain (loss), net on derivatives	$ (112)	$ (17)
Realized gain (loss), net on derivatives	$ (57)	$ 1