Long-Term Debt (Details) (USD $)	3 Months Ended
	Feb. 29, 2012	Sep. 30, 2007	Nov. 30, 2011	Nov. 12, 2011
Summary of long-term debt carrying values including unamortized discounts and premiums
Long-term debt	$ 4,746,077,000		$ 4,608,926,000
Revolving credit facility	950,000,000			950,000,000
Effective interest rates	0.375%
Gain on repurchase of long-term debt	(9,898,000)
Expiry date of term loan	Feb. 02, 2013
Long-Term Debt (Textual) [Abstract]
Debentures convertible at holder's options	1) Companies common stock price is greater than 130% of the conversion price for at least 20 trading days in a period of 30 consecutive trading days; 2) if the trading price per debenture is less than 95% of the price of companies common stock times the conversion ratio for any 10 consecutive trading days; 3) if the debentures are called for redemption; or 4) upon the occurrence of specific corporate actions.
Description of Contingent Debenture Interest Payment	Beginning on November 1, 2017, contingent interest will accrue at 0.375% if the average trading price of a debenture for 5 trading days ending on and including the third trading day immediately preceding a six-month interest period equals or exceed $1,200 per $1,000 debenture
Cash proceeds on termination of interest rate swap agreement		8,500,000
Description to Redeem the debentures for par, plus accrued interest	On or after November 1, 2012 if the price of our common stock is greater than 130% of the conversion price for at least 20 days in a period of 30 consecutive trading days and we may redeem the debentures for par, plus accrued interest, at our election any time on or after November 1, 2017
Borrowed unsecured credit facility				250,000,000
Borrowings outstanding under the Credit Facility	250,000,000
Reduction in long term debt	37,100,000
Outstanding short term borrowings	100,000,000		52,721,000
Conversion price percentage	130.00%
Earliest period of conversion price	P20D
Latest period of conversion price	P30D
Trading price per debenture related to common stock	95.00%
Consecutive trading days	P10D
Trading price of contingent interest	1,200
Unsecured Debt [Member]
Summary of long-term debt carrying values including unamortized discounts and premiums
Long-term debt	4,496,077,000		4,508,926,000
7.75% Senior Notes, due 2012 [Member]
Summary of long-term debt carrying values including unamortized discounts and premiums
Interest rates	7.75%
Effective interest rates	8.08%
Par value of notes issued		200,000,000
Portion of interest expense amortized		1,900,000
Amount remained to be amortized	37,000
Expiry date of term loan	Mar. 15, 2012
7.75% Senior Notes, due 2012 [Member] | Unsecured Debt [Member]
Summary of long-term debt carrying values including unamortized discounts and premiums
Long-term debt	253,269,000		254,926,000
5.875% Senior Notes, due 2014 [Member]
Summary of long-term debt carrying values including unamortized discounts and premiums
Interest rates	5.875%
Effective interest rates	6.00%
5.875% Senior Notes, due 2014 [Member] | Unsecured Debt [Member]
Summary of long-term debt carrying values including unamortized discounts and premiums
Long-term debt	249,363,000		249,298,000
3.875% Senior Note, due 2015 [Member]
Summary of long-term debt carrying values including unamortized discounts and premiums
Interest rates	3.875%
Effective interest rates	3.92%
3.875% Senior Note, due 2015 [Member] | Unsecured Debt [Member]
Summary of long-term debt carrying values including unamortized discounts and premiums
Long-term debt	499,235,000		499,187,000
5.5% Senior Notes, due 2016 [Member]
Summary of long-term debt carrying values including unamortized discounts and premiums
Interest rates	5.50%
Effective interest rates	5.57%
5.5% Senior Notes, due 2016 [Member] | Unsecured Debt [Member]
Summary of long-term debt carrying values including unamortized discounts and premiums
Long-term debt	349,095,000		349,045,000
5.125% Senior Notes, due 2018 [Member]
Summary of long-term debt carrying values including unamortized discounts and premiums
Interest rates	5.125%
Effective interest rates	5.18%
5.125% Senior Notes, due 2018 [Member] | Unsecured Debt [Member]
Summary of long-term debt carrying values including unamortized discounts and premiums
Long-term debt	768,133,000		782,598,000
8.5% Senior Notes, due 2019 [Member]
Summary of long-term debt carrying values including unamortized discounts and premiums
Interest rates	8.50%
Effective interest rates	8.31%
8.5% Senior Notes, due 2019 [Member] | Unsecured Debt [Member]
Summary of long-term debt carrying values including unamortized discounts and premiums
Long-term debt	707,593,000		707,787,000
6.875% Senior Note, due 2021 [Member]
Summary of long-term debt carrying values including unamortized discounts and premiums
Interest rates	6.875%
Effective interest rates	6.99%
6.875% Senior Note, due 2021 [Member] | Unsecured Debt [Member]
Summary of long-term debt carrying values including unamortized discounts and premiums
Long-term debt	545,895,000		545,816,000
6.45% Senior Debentures, due 2027 [Member]
Summary of long-term debt carrying values including unamortized discounts and premiums
Interest rates	6.45%
Effective interest rates	6.55%
6.45% Senior Debentures, due 2027 [Member] | Unsecured Debt [Member]
Summary of long-term debt carrying values including unamortized discounts and premiums
Long-term debt	346,695,000		346,664,000
3.875% Convertible Senior Debentures, due, 2029 [Member]
Summary of long-term debt carrying values including unamortized discounts and premiums
Interest rates	3.875%
Effective interest rates	7.20%
Par value of notes issued	345,000,000
3.875% convertible senior debenture Principal amount	1,000
Conversion price of common stock	$ 37.94
Debt Instrument Convertible Conversion Ratio	26.3603
3.875% Convertible Senior Debentures, due, 2029 [Member] | Unsecured Debt [Member]
Summary of long-term debt carrying values including unamortized discounts and premiums
Long-term debt	283,994,000		280,832,000
6.25% Senior Debentures, due 2036 [Member]
Summary of long-term debt carrying values including unamortized discounts and premiums
Interest rates	6.25%
Effective interest rates	6.37%
6.25% Senior Debentures, due 2036 [Member] | Unsecured Debt [Member]
Summary of long-term debt carrying values including unamortized discounts and premiums
Long-term debt	492,805,000		492,773,000
Credit facility, due 2014 [Member] | Secured Debt [Member]
Summary of long-term debt carrying values including unamortized discounts and premiums
Long-term debt	$ 250,000,000		$ 100,000,000