Fair Value Disclosures (Details 1) (USD $) In Thousands, unless otherwise specified	Nov. 30, 2013 Convertible Senior Notes Due Two Thousand Nineteen At One Point Three Seven Five Percent [Member]	Nov. 30, 2013 Carrying Value Level 2	Nov. 30, 2012 Carrying Value Level 2	Nov. 30, 2013 Estimated Fair Value Level 2	Nov. 30, 2012 Estimated Fair Value Level 2	Jun. 30, 2004 Senior Notes [Member] Senior notes due 2011 at 6 3/8%	Nov. 30, 2013 Senior Notes [Member] Senior notes due February 1, 2014 at 5 3/4%	Nov. 30, 2012 Senior Notes [Member] Senior notes due February 1, 2014 at 5 3/4%	Jan. 28, 2004 Senior Notes [Member] Senior notes due February 1, 2014 at 5 3/4%	Nov. 30, 2013 Senior Notes [Member] Senior notes due January 15, 2015 at 5 7/8%	Nov. 30, 2012 Senior Notes [Member] Senior notes due January 15, 2015 at 5 7/8%	Dec. 15, 2004 Senior Notes [Member] Senior notes due January 15, 2015 at 5 7/8%	Nov. 30, 2013 Senior Notes [Member] Senior notes due June 15, 2015 at 6 1/4%	Nov. 30, 2012 Senior Notes [Member] Senior notes due June 15, 2015 at 6 1/4%	Jun. 02, 2005 Senior Notes [Member] Senior notes due June 15, 2015 at 6 1/4%	Nov. 30, 2013 Senior Notes [Member] Senior notes due September 15, 2017 at 9.10%	Nov. 30, 2012 Senior Notes [Member] Senior notes due September 15, 2017 at 9.10%	Jul. 30, 2009 Senior Notes [Member] Senior notes due September 15, 2017 at 9.10%	Nov. 30, 2013 Senior Notes [Member] Senior notes due June 15, 2018 at 7 1/4%	Nov. 30, 2012 Senior Notes [Member] Senior notes due June 15, 2018 at 7 1/4%	Apr. 03, 2006 Senior Notes [Member] Senior notes due June 15, 2018 at 7 1/4%	Nov. 30, 2013 Senior Notes [Member] Senior notes due March 15, 2020 at 8.00%	Nov. 30, 2012 Senior Notes [Member] Senior notes due March 15, 2020 at 8.00%	Feb. 07, 2012 Senior Notes [Member] Senior notes due March 15, 2020 at 8.00%	Nov. 30, 2013 Senior Notes [Member] Senior notes due September 15, 2022 at 7.50%	Nov. 30, 2012 Senior Notes [Member] Senior notes due September 15, 2022 at 7.50%	Jul. 31, 2012 Senior Notes [Member] Senior notes due September 15, 2022 at 7.50%	Nov. 30, 2013 Senior Notes [Member] Senior notes due December 15, 2021 at 7.00%	Oct. 29, 2013 Senior Notes [Member] Senior notes due December 15, 2021 at 7.00%
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value		$ 1,906,883	$ 1,670,504	$ 2,069,325	$ 1,831,596
Senior notes, rate	1.375%					6.375%	5.75%	5.75%	5.75%	5.88%	5.88%	5.875%	6.25%	6.25%	6.25%	9.10%	9.10%	9.10%	7.25%	7.25%	7.25%	8.00%	8.00%	8.00%	7.50%	7.50%	7.50%	7.00%	7.00%
Convertible Debt, Fair Value Disclosures		$ 230,000	$ 0	$ 224,825	$ 0