Partnership's Outstanding Debt (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Long-term debt	$ 4,295,055	$ 3,249,230
5.875 Percent Senior Notes due April 2021
Debt Instrument [Line Items]
Long-term debt	750,000	750,000
Premium on Long-term Debt	5,055	5,730
6.125 Percent Senior Notes due July 2022
Debt Instrument [Line Items]
Long-term debt	750,000	750,000
4.875 Percent Senior Notes due May 2023
Debt Instrument [Line Items]
Long-term debt	1,400,000	1,400,000
4.875 Percent Senior Notes due March 2024
Debt Instrument [Line Items]
Long-term debt	750,000
Revolving Credit Facility
Debt Instrument [Line Items]
Long-term debt	$ 640,000	$ 343,500