Long Term Incentive and Retirement Plans - Additional Information (Detail) (USD $)	12 Months Ended																	1 Months Ended	12 Months Ended			1 Months Ended					1 Months Ended					1 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Restricted phantom units		Dec. 31, 2012 Restricted phantom units		Dec. 31, 2011 Restricted phantom units		Dec. 31, 2013 2009 UAR Agreements	Dec. 31, 2009 2009 UAR Agreements	Dec. 31, 2013 2012 UAR Agreements	Dec. 31, 2012 2012 UAR Agreements	Dec. 31, 2013 2013 UAR Agreements	Dec. 31, 2013 Unit appreciation rights	Dec. 31, 2012 Unit appreciation rights	Dec. 31, 2011 Unit appreciation rights	Dec. 31, 2006 Employee Two Thousand Six Unit Appreciation Rights	Dec. 31, 2011 Employee Two Thousand Six Unit Appreciation Rights	Dec. 31, 2009 Employee Two Thousand Six Unit Appreciation Rights	Dec. 31, 2006 Employee Two Thousand Six Unit Appreciation Rights	Dec. 31, 2012 Employee 2012 UAR Agreements	Oct. 31, 2013 Employee 2013 UAR Agreements	May 31, 2013 Employee 2013 UAR Agreements	Nov. 30, 2006 Director Restricted phantom units	Dec. 31, 2013 Director Restricted phantom units	Nov. 30, 2012 Executive Officer Restricted phantom units	Dec. 31, 2009 Executive Officer Restricted phantom units	Nov. 30, 2012 Executive Officer Restricted phantom units Lease Years 6-20	Nov. 30, 2012 Executive Officer Restricted phantom units Lease Years 21-25	Nov. 30, 2012 Executive Officer Restricted phantom units Lease Years 26- 35	Nov. 30, 2012 Executive Officer Restricted phantom units Maximum	Dec. 31, 2009 Employees And Non-Employee Directors 2009 UAR Agreements
Long Term Debt Maturities Repayments Of Principal [Line Items]
Long-Term Incentive Plan, common units permitted for grant	1,124,000
Long-Term Incentive Plan, plan term	10 years
Long-Term Incentive Plan, units granted				18,890	[1]	58,836	[1]	10,643	[1]		814,000	80,500		52,500	52,500	80,500					120,000				3,000		45,000	20,000
Long-Term Incentive Plan, number of directors																										5
Long-Term Incentive Plan, units vesting period																																3 years
Long-Term Incentive Plan, vesting number of units																													15,000	15,000	15,000
Total compensation expense for unit awards	$ 1,370,000	$ 916,000	$ 773,000	$ 800,000		$ 400,000		$ 300,000							$ 500,000	$ 500,000	$ 500,000
Long-Term Incentive Plan, Unrecognized compensation cost				700,000		1,000,000									200,000
Long-Term Incentive Plan, units vested																				120,000
Long-Term Incentive Plan, units exercised																			120,000
Unit Appreciation Rights, Base price per unit																		$ 24.14				$ 24.36	$ 25.61	$ 26.68									$ 18.80
Long-Term Incentive Plan, units outstanding										565,716		55,500		52,500
UARs granted under LTIP, contractual term										5 years		5 years		5 years
Long-Term incentive plan, fair value per unit				$ 25.29		$ 23.84		$ 27.79			$ 2.39		$ 3.70	$ 2.09
Long-Term incentive plan, aggregate fair value											1,900,000		300,000	100,000
Long-Term Incentive Plan, compensation cost expected to be recognized in one year															$ 100,000
Unrecognized compensation cost related to non-vested UARs, weighted-average recognition period															1 year
Common units issued as a result of UARs exercise															34,096	19,452	24,682
Retirement savings plan, employee contribution percentage	15.00%

[1] The weighted-average price for unit awards on the date of grant was $25.29, $23.84 and $27.79 for the years ended December 31, 2013, 2012 and 2011, respectively.