Fair Value Measurements, Derivative Instruments and Hedging Activities - Fuel Derivatives Outstanding (Detail)	3 Months Ended
	Feb. 28, 2014 bbl
Fuel Derivatives 2014 Maturity November 2011 Transaction Date
Derivative [Line Items]
Barrels	1,584,000	[1]
Weighted-Average Floor Price	85	[1]
Weighted-Average Ceiling Price	114	[1]
Derivative Inception Month And Year	2011-11	[1]
Fuel Derivatives 2014 Maturity February 2012 Transaction Date
Derivative [Line Items]
Barrels	1,584,000	[1]
Weighted-Average Floor Price	88	[1]
Weighted-Average Ceiling Price	125	[1]
Derivative Inception Month And Year	2012-02	[1]
Fuel Derivatives 2014 Maturity June 2012 Transaction Date
Derivative [Line Items]
Barrels	1,782,000	[1]
Weighted-Average Floor Price	71	[1]
Weighted-Average Ceiling Price	116	[1]
Derivative Inception Month And Year	2012-06	[1]
Fuel Derivatives 2014 Maturity May 2013 Transaction
Derivative [Line Items]
Barrels	1,296,000	[1]
Weighted-Average Floor Price	85	[1]
Weighted-Average Ceiling Price	108	[1]
Derivative Inception Month And Year	2013-05	[1]
Fuel Derivatives 2014 Maturity
Derivative [Line Items]
Barrels	6,246,000	[1]
Percent of Estimated Fuel Consumption	46.00%	[1]
Fuel Derivatives 2015 Maturity November 2011 Transaction Date
Derivative [Line Items]
Barrels	2,160,000	[1]
Weighted-Average Floor Price	80	[1]
Weighted-Average Ceiling Price	114	[1]
Derivative Inception Month And Year	2011-11	[1]
Fuel Derivatives 2015 Maturity February 2012 Transaction Date
Derivative [Line Items]
Barrels	2,160,000	[1]
Weighted-Average Floor Price	80	[1]
Weighted-Average Ceiling Price	125	[1]
Derivative Inception Month And Year	2012-02	[1]
Fuel Derivatives 2015 Maturity June 2012 Transaction Date
Derivative [Line Items]
Barrels	1,236,000	[1]
Weighted-Average Floor Price	74	[1]
Weighted-Average Ceiling Price	110	[1]
Derivative Inception Month And Year	2012-06	[1]
Fuel Derivatives 2015 Maturity April 2013 Transaction Date
Derivative [Line Items]
Barrels	1,044,000	[1]
Weighted-Average Floor Price	80	[1]
Weighted-Average Ceiling Price	111	[1]
Derivative Inception Month And Year	2013-04	[1]
Fuel Derivatives 2015 Maturity May 2013 Transaction Date
Derivative [Line Items]
Barrels	1,884,000	[1]
Weighted-Average Floor Price	80	[1]
Weighted-Average Ceiling Price	110	[1]
Derivative Inception Month And Year	2013-05	[1]
Fuel Derivatives 2015 Maturity
Derivative [Line Items]
Barrels	8,484,000	[1]
Percent of Estimated Fuel Consumption	46.00%
Fuel Derivatives 2016 Maturity June 2012 Transaction Date
Derivative [Line Items]
Barrels	3,564,000	[1]
Weighted-Average Floor Price	75	[1]
Weighted-Average Ceiling Price	108	[1]
Derivative Inception Month And Year	2012-06	[1]
Fuel Derivatives 2016 Maturity February 2013 Transaction Date
Derivative [Line Items]
Barrels	2,160,000	[1]
Weighted-Average Floor Price	80	[1]
Weighted-Average Ceiling Price	120	[1]
Derivative Inception Month And Year	2013-02	[1]
Fuel Derivatives 2016 Maturity April 2013 Transaction Date
Derivative [Line Items]
Barrels	3,000,000	[1]
Weighted-Average Floor Price	75	[1]
Weighted-Average Ceiling Price	115	[1]
Derivative Inception Month And Year	2013-04	[1]
Fuel Derivatives 2016 Maturity
Derivative [Line Items]
Barrels	8,724,000	[1]
Percent of Estimated Fuel Consumption	47.00%	[1]
Fuel Derivatives 2017 Maturity February 2013 Transaction Date
Derivative [Line Items]
Barrels	3,276,000	[1]
Weighted-Average Floor Price	80	[1]
Weighted-Average Ceiling Price	115	[1]
Derivative Inception Month And Year	2013-02	[1]
Fuel Derivatives 2017 Maturity April 2013 Transaction Date
Derivative [Line Items]
Barrels	2,028,000	[1]
Weighted-Average Floor Price	75	[1]
Weighted-Average Ceiling Price	110	[1]
Derivative Inception Month And Year	2013-04	[1]
Fuel Derivatives 2017 Maturity Date January 2014 Transaction Date
Derivative [Line Items]
Barrels	1,800,000	[1]
Weighted-Average Floor Price	75
Weighted-Average Ceiling Price	114
Derivative Inception Month And Year	2014-01	[1]
Fuel Derivatives 2017 Maturity
Derivative [Line Items]
Barrels	7,104,000	[1]
Percent of Estimated Fuel Consumption	38.00%	[1]
Fuel Derivatives 2018 Maturity January 2014 Transaction Date
Derivative [Line Items]
Weighted-Average Floor Price	75
Weighted-Average Ceiling Price	110
Fuel Derivatives 2018 Maturity
Derivative [Line Items]
Barrels	2,700,000	[1]
Percent of Estimated Fuel Consumption	15.00%	[1]

[1] Fuel derivatives mature evenly over each month within the above fiscal periods.