Long-Term Debt (Details) (USD $)	1 Months Ended	3 Months Ended
	Jan. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
Long-Term Debt
Long-term debt, net of discounts		$ 3,022,521,000	$ 2,523,051,000
Long-term debt, discounts		7,479,000	8,061,000
Ownership of the Partnership in its guarantor subsidiaries (as a percent)		100.00%
Pre-tax loss on repurchase of debt	38,500,000
Non-cash write-off of the unamortized discount and deferred finance costs	7,000,000
Payments of premiums on redemption of long-term debt	31,500,000	31,516,000
Credit Facility
Long-Term Debt
Applicable interest rate (as a percent)		4.75%
Ownership of the Partnership in its guarantor subsidiaries (as a percent)		100.00%
Borrowings outstanding		0
Letters of credit outstanding amount		11,300,000
Credit facility remaining borrowing capacity		1,188,700,000
Amount available for borrowing based on financial covenant requirements		145,300,000
Senior Notes
Long-Term Debt
Estimate aggregate fair value of debt		3,180,100,000	2,763,100,000
2018 Senior Notes, 8.75% interest, issued April and May 2008
Long-Term Debt
Long-term debt, net of discounts			81,003,000
Debt instrument, stated interest rate percentage	8.75%	8.75%
Long-term debt, discounts		0	109,000
Amount of debt repurchased	81,100,000
2020 Senior Notes, 6.75% interest, issued November 2010 and due November 2020
Long-Term Debt
Long-term debt, net of discounts		500,000,000	500,000,000
Debt instrument, stated interest rate percentage		6.75%
2021 Senior Notes, 6.5% interest, issued February and March 2011 and due August 2021
Long-Term Debt
Long-term debt, net of discounts		324,479,000	499,174,000
Debt instrument, stated interest rate percentage	6.50%	6.50%
Long-term debt, discounts		521,000	826,000
Amount of debt repurchased	175,000,000
2022 Senior Notes, 6.25% interest, issued October 2011 and due June 2022
Long-Term Debt
Long-term debt, net of discounts		455,000,000	700,000,000
Debt instrument, stated interest rate percentage	6.25%	6.25%
Amount of debt repurchased	245,000,000
2023A Senior Notes, 5.5% interest, issued August 2012 and due February 2023
Long-Term Debt
Long-term debt, net of discounts		743,042,000	742,874,000
Debt instrument, stated interest rate percentage		5.50%
Long-term debt, discounts		6,958,000	7,126,000
2023B Senior Notes, 4.5% interest, issued January 2013 and due July 2023
Long-Term Debt
Long-term debt, net of discounts		1,000,000,000
Debt instrument, stated interest rate percentage	4.50%	4.50%
Aggregate principal amount of public offering	1,000,000,000
Proceeds from issuance of senior notes, net of underwriting fees and the other expenses of the offering	$ 986,000,000