Long-Term Debt	6 Months Ended
Jun. 30, 2013
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt: In July 2010, the Partnership issued $405 million of 9.125% senior unsecured notes, maturing in 2018, in a private placement, including $5.6 million of Original Issue Discount ("OID") to yield 9.375%. Concurrently with this offering, the Partnership entered into a new $1,435 million credit agreement (the "2010 Credit Agreement”), which included a $1,175 million senior secured term loan facility and a $260 million senior secured revolving credit facility. The net proceeds from the offering of the notes, along with borrowings under the 2010 Credit Agreement, were used to repay in full all amounts outstanding under the previous credit facilities. The facilities provided under the 2010 Credit Agreement were collateralized by substantially all of the assets of the Partnership. The Partnership's $405 million of senior unsecured notes pay interest semi-annually in February and August, with the principal due in full on August 1, 2018. The notes may be redeemed, in whole or in part, at any time prior to August 1, 2014 at a price equal to 100% of the principal amount of the notes redeemed plus a “make-whole” premium together with accrued and unpaid interest, if any, to the redemption date. Thereafter, the notes may be redeemed, in whole or in part, at various prices depending on the date redeemed. Prior to August 1, 2013, up to 35% of the notes may be redeemed with the net cash proceeds of certain equity offerings at 109.125%. Terms of the 2010 Credit Agreement included a revolving credit facility of a combined $260 million. Under the 2010 Credit Agreement, the Canadian portion of the revolving credit facility had a limit of $15 million. U.S. denominated loans made under the revolving credit facility bore interest at a rate of LIBOR plus 400 basis points (bps) (with no LIBOR floor). Canadian denominated loans made under the Canadian portion of the facility bore interest at a rate of LIBOR plus 400 bps (with no LIBOR floor). The revolving credit facility, which was scheduled to mature in July 2015, also provided for the issuance of documentary and standby letters of credit. The Amended 2010 Credit Agreement required the Partnership to pay a commitment fee of 50 bps per annum on the unused portion of the credit facilities. In February 2011, the Partnership amended the 2010 Credit Agreement (as so amended, the “Amended 2010 Credit Agreement”) and extended the maturity date of the term loan portion of the credit facilities by one year. The extended U.S. term loan was scheduled to mature in December 2017 and bore interest at a rate of LIBOR plus 300 bps, with a LIBOR floor of 100 bps. In March 2013, the Partnership issued $500 million of 5.25% senior unsecured notes, maturing in 2021, in a private placement, with no OID. Concurrently with this offering, the Partnership entered into a new $885 million credit agreement (the "2013 Credit Agreement"), which included a $630 million senior secured term loan facility and a $255 million senior secured revolving credit facility. The terms of the senior secured term loan facility include a maturity date of March 6, 2020 and bear interest at a rate of LIBOR plus 250 bps with a LIBOR floor of 75 bps. The term loan amortizes at $6.3 million annually. The net proceeds from the notes and borrowings under the 2013 Credit Agreement were used to repay in full all amounts outstanding under the previous credit facilities. The facilities provided under the 2013 Credit Agreement are collateralized by substantially all of the assets of the Partnership. Terms of the 2013 Credit Agreement include a revolving credit facility of a combined $255 million. Under the 2013 Credit Agreement, the Canadian portion of the revolving credit facility has a sub-limit of $15 million. U.S. denominated and Canadian denominated loans made under the revolving credit facility bear interest at a rate of LIBOR plus 225 bps (with no LIBOR floor). The revolving credit facility is scheduled to mature in March 2018 and also provides for the issuance of documentary and standby letters of credit. The 2013 Credit Agreement requires the Partnership to pay a commitment fee of 50 bps per annum on the unused portion of the credit facilities. The 2013 Credit Agreement requires the Partnership to maintain specified financial ratios, which if breached for any reason, including a decline in operating results, could result in an event of default under the agreement. The most restrictive of these ratios is the Consolidated Leverage Ratio which is measured quarterly on a trailing-twelve month basis. The Consolidated Leverage Ratio is set at 6.25x consolidated total debt (excluding the revolving debt)-to-Consolidated EBITDA and will remain at that level through the end of the first quarter in 2014, and the ratio will decrease each second quarter beginning with the second quarter of 2014. As of June 30, 2013, the Partnership’s Consolidated Leverage Ratio was 3.81x, providing $157.0 million of consolidated EBITDA cushion on the ratio as of the end of the second quarter. The Partnership was in compliance with all other covenants under the 2013 Credit Agreement as of June 30, 2013. The 2013 Credit Agreement also includes provisions that allow the Partnership to make restricted payments of up to $60 million annually, so long as no default or event of default has occurred and is continuing. These restricted payments are not subject to any specific covenants. Additional restricted payments are allowed to be made based on an Excess-Cash-Flow formula, should the Partnership’s pro-forma Consolidated Leverage Ratio be less than or equal to 5.00x. Per the terms of the indenture governing the Partnership's notes maturing in 2018, which is more restrictive than the indenture governing the Partnership's notes maturing in 2021, the ability to make restricted payments in 2013 and beyond is permitted should the Partnership's trailing-twelve-month Total-Indebtedness-to-Consolidated-Cash-Flow Ratio be less than or equal to 4.75x, measured on a quarterly basis. The Partnership's $500 million of senior unsecured notes pay interest semi-annually in March and September, with the principal due in full on March 15, 2021. The notes may be redeemed, in whole or in part, at any time prior to March 15, 2016 at a price equal to 100% of the principal amount of the notes redeemed plus a “make-whole” premium together with accrued and unpaid interest, if any, to the redemption date. Thereafter, the notes may be redeemed, in whole or in part, at various prices depending on the date redeemed. Prior to March 15, 2016, up to 35% of the notes may be redeemed with the net cash proceeds of certain equity offerings at 105.25%.

Long-Term Debt:

In July 2010, the Partnership issued $405 million of 9.125% senior unsecured notes, maturing in 2018, in a private placement, including $5.6 million of Original Issue Discount ("OID") to yield 9.375%. Concurrently with this offering, the Partnership entered into a new $1,435 million credit agreement (the "2010 Credit Agreement”), which included a $1,175 million senior secured term loan facility and a $260 million senior secured revolving credit facility. The net proceeds from the offering of the notes, along with borrowings under the 2010 Credit Agreement, were used to repay in full all amounts outstanding under the previous credit facilities. The facilities provided under the 2010 Credit Agreement were collateralized by substantially all of the assets of the Partnership.

The Partnership's $405 million of senior unsecured notes pay interest semi-annually in February and August, with the principal due in full on August 1, 2018. The notes may be redeemed, in whole or in part, at any time prior to August 1, 2014 at a price equal to 100% of the principal amount of the notes redeemed plus a “make-whole” premium together with accrued and unpaid interest, if any, to the redemption date. Thereafter, the notes may be redeemed, in whole or in part, at various prices depending on the date redeemed. Prior to August 1, 2013, up to 35% of the notes may be redeemed with the net cash proceeds of certain equity offerings at 109.125%.

Terms of the 2010 Credit Agreement included a revolving credit facility of a combined $260 million. Under the 2010 Credit Agreement, the Canadian portion of the revolving credit facility had a limit of $15 million. U.S. denominated loans made under the revolving credit facility bore interest at a rate of LIBOR plus 400 basis points (bps) (with no LIBOR floor). Canadian denominated loans made under the Canadian portion of the facility bore interest at a rate of LIBOR plus 400 bps (with no LIBOR floor). The revolving credit facility, which was scheduled to mature in July 2015, also provided for the issuance of documentary and standby letters of credit. The Amended 2010 Credit Agreement required the Partnership to pay a commitment fee of 50 bps per annum on the unused portion of the credit facilities.

In February 2011, the Partnership amended the 2010 Credit Agreement (as so amended, the “Amended 2010 Credit Agreement”) and extended the maturity date of the term loan portion of the credit facilities by one year. The extended U.S. term loan was scheduled to mature in December 2017 and bore interest at a rate of LIBOR plus 300 bps, with a LIBOR floor of 100 bps.

In March 2013, the Partnership issued $500 million of 5.25% senior unsecured notes, maturing in 2021, in a private placement, with no OID. Concurrently with this offering, the Partnership entered into a new $885 million credit agreement (the "2013 Credit Agreement"), which included a $630 million senior secured term loan facility and a $255 million senior secured revolving credit facility. The terms of the senior secured term loan facility include a maturity date of March 6, 2020 and bear interest at a rate of LIBOR plus 250 bps with a LIBOR floor of 75 bps. The term loan amortizes at $6.3 million annually. The net proceeds from the notes and borrowings under the 2013 Credit Agreement were used to repay in full all amounts outstanding under the previous credit facilities. The facilities provided under the 2013 Credit Agreement are collateralized by substantially all of the assets of the Partnership.

Terms of the 2013 Credit Agreement include a revolving credit facility of a combined $255 million. Under the 2013 Credit Agreement, the Canadian portion of the revolving credit facility has a sub-limit of $15 million. U.S. denominated and Canadian denominated loans made under the revolving credit facility bear interest at a rate of LIBOR plus 225 bps (with no LIBOR floor). The revolving credit facility is scheduled to mature in March 2018 and also provides for the issuance of documentary and standby letters of credit. The 2013 Credit Agreement requires the Partnership to pay a commitment fee of 50 bps per annum on the unused portion of the credit facilities.

The 2013 Credit Agreement requires the Partnership to maintain specified financial ratios, which if breached for any reason, including a decline in operating results, could result in an event of default under the agreement. The most restrictive of these ratios is the Consolidated Leverage Ratio which is measured quarterly on a trailing-twelve month basis. The Consolidated Leverage Ratio is set at 6.25x consolidated total debt (excluding the revolving debt)-to-Consolidated EBITDA and will remain at that level through the end of the first quarter in 2014, and the ratio will decrease each second quarter beginning with the second quarter of 2014. As of June 30, 2013, the Partnership’s Consolidated Leverage Ratio was 3.81x, providing $157.0 million of consolidated EBITDA cushion on the ratio as of the end of the second quarter. The Partnership was in compliance with all other covenants under the 2013 Credit Agreement as of June 30, 2013.

The 2013 Credit Agreement also includes provisions that allow the Partnership to make restricted payments of up to $60 million annually, so long as no default or event of default has occurred and is continuing. These restricted payments are not subject to any specific covenants. Additional restricted payments are allowed to be made based on an Excess-Cash-Flow formula, should the Partnership’s pro-forma Consolidated Leverage Ratio be less than or equal to 5.00x. Per the terms of the indenture governing the Partnership's notes maturing in 2018, which is more restrictive than the indenture governing the Partnership's notes maturing in 2021, the ability to make restricted payments in 2013 and beyond is permitted should the Partnership's trailing-twelve-month Total-Indebtedness-to-Consolidated-Cash-Flow Ratio be less than or equal to 4.75x, measured on a quarterly basis.

The Partnership's $500 million of senior unsecured notes pay interest semi-annually in March and September, with the principal due in full on March 15, 2021. The notes may be redeemed, in whole or in part, at any time prior to March 15, 2016 at a price equal to 100% of the principal amount of the notes redeemed plus a “make-whole” premium together with accrued and unpaid interest, if any, to the redemption date. Thereafter, the notes may be redeemed, in whole or in part, at various prices depending on the date redeemed. Prior to March 15, 2016, up to 35% of the notes may be redeemed with the net cash proceeds of certain equity offerings at 105.25%.