Cash Distributions to Limited Partners - Summary of Cash Distributions Paid to Limited Partners (Detail) (USD $)	3 Months Ended												12 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Cash Distribution per Limited Partnership Unit	$ 20.33	$ 20.92	$ 19.64	$ 19.25	$ 20.28	$ 19.56	$ 17.10	$ 19.70	$ 19.19	$ 19.22	$ 17.12	$ 17.45	$ 80.14	$ 76.64	$ 72.98
Weighted Average Number of Units Outstanding	8,751	8,751	8,751	8,751	8,751	8,751	8,751	8,751	8,751	8,751	8,751	8,751	8,751	8,751	8,751
Number of Units Outstanding at the End of the Quarter	8,751	8,751	8,751	8,751	8,751	8,751	8,751	8,751	8,751	8,751	8,751	8,751	8,751	8,751	8,751