Debt - Additional Information (Detail) (USD $)	1 Months Ended	6 Months Ended	9 Months Ended							3 Months Ended				3 Months Ended				6 Months Ended
	Jun. 30, 2011	Jun. 30, 2011	Sep. 30, 2012	Dec. 31, 2007	Jun. 30, 2011 6.50% notes due 2016 [Member]	Sep. 30, 2012 Minimum [Member]	Sep. 30, 2012 Maximum [Member]	Dec. 31, 2011 Bank credit facility expiring November 16, 2012 [Member]	Dec. 31, 2011 Bank credit facility expiring December 15, 2016 [Member]	Jun. 30, 2011 5.60% notes due 2012 [Member]	Sep. 30, 2012 5.60% notes due 2012 [Member]	Dec. 31, 2011 5.60% notes due 2012 [Member]	Sep. 30, 2011 5.60% notes due 2012 [Member]	Jun. 30, 2011 6.30% notes due 2013 [Member]	Sep. 30, 2012 6.30% notes due 2013 [Member]	Dec. 31, 2011 6.30% notes due 2013 [Member]	Sep. 30, 2011 6.30% notes due 2013 [Member]	Jun. 30, 2011 6.30% notes due 2013 [Member] 5.60% notes due 2012 [Member]	Sep. 30, 2012 10.125% notes due 2015 [Member]	Dec. 31, 2011 10.125% notes due 2015 [Member]	Sep. 30, 2011 10.125% notes due 2015 [Member]	Jun. 30, 2011 10.125% notes due 2015 [Member]	Sep. 30, 2012 6.50% notes due 2016 [Member]	Dec. 31, 2011 6.50% notes due 2016 [Member]	Sep. 30, 2011 6.50% notes due 2016 [Member]	Jun. 30, 2011 6.50% notes due 2016 [Member]	Sep. 30, 2012 7.50% notes due 2021 [Member]	Sep. 30, 2012 6.40% notes due 2017 [Member]	Dec. 31, 2011 6.40% notes due 2017 [Member]	Sep. 30, 2011 6.40% notes due 2017 [Member]	Sep. 30, 2012 7.00% notes due 2018 [Member]	Dec. 31, 2011 7.00% notes due 2018 [Member]	Sep. 30, 2011 7.00% notes due 2018 [Member]	Sep. 30, 2012 10.375% notes due 2018 [Member]	Dec. 31, 2011 10.375% notes due 2018 [Member]	Sep. 30, 2011 10.375% notes due 2018 [Member]	Sep. 30, 2012 7.15% notes due 2037 [Member]	Dec. 31, 2011 7.15% notes due 2037 [Member]	Sep. 30, 2011 7.15% notes due 2037 [Member]	Jun. 30, 2011 7.50% notes due 2021 [Member]	Jun. 30, 2011 Floating Rate Term Loan Due 2015 [Member]	Jun. 30, 2011 5.60% notes due 2012 [Member]
Debt Instrument [Line Items]
Decrease in unamortized discounts											$ 9,000	$ 49,000	$ 61,000		$ 46,000	$ 92,000	$ 107,000		$ 284,000	$ 338,000	$ 355,000							$ 117,000	$ 131,000	$ 135,000	$ 279,000	$ 307,000	$ 316,000	$ 1,363,000	$ 1,474,000	$ 1,509,000	$ 637,000	$ 643,000	$ 644,000
Effective interest rate											6.57%				7.48%				9.59%				6.02%				7.75%	7.41%			7.87%			10.62%			8.05%
Increase (decrease) in unamortized deferred gain realized																			3,195,000	3,802,000	3,995,000		15,887,000	18,293,000	19,072,000
Amount of facility			600,000,000					1,500,000,000	600,000,000
Interest rate margin						1.75%	2.25%
Borrowing capacity description			Borrowing capacity fluctuates with the level of eligible accounts receivable and inventory and may be less than $600,000,000 at any point in time.
Variable rate basis for borrowings			1, 2, 3 or 6 months
Applicable margin			1.75%
Payment period to be classified as short-term debt			1 year
Long-term notes face amount	1,100,000,000	1,100,000,000		325,000,000	500,000,000													274,999,000								500,000,000														600,000,000	450,000,000
Coupon rate of notes										5.60%				6.30%								10.125%				6.50%														7.50%		6.30%
Purchase of long term notes										165,443,000				109,556,000
Outstanding amount under revolving credit facility repaid	275,000,000
Recognition of unamortized deferred financing costs		2,423,000
Total consideration paid for debt																		294,533,000
Premium paid for purchase of debt																		19,534,000
Expenses related to partial termination of debt	4,711,000
Combined expense recognized as a component of interest expense	$ 24,245,000