Results by Quarter - Summary of Results by Quarter (Detail) (USD $)	3 Months Ended								12 Months Ended
	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, 2013	Dec. 31, 2012	Dec. 31, 2011
Quarterly Financial Information Disclosure [Abstract]
RENTAL REVENUES	$ 195,376	$ 195,130	$ 194,907	$ 181,021	$ 184,548	$ 188,947	$ 184,786	$ 179,443	$ 766,434	$ 737,724	$ 733,960
Net income	$ 174,494	$ 176,260	$ 173,203	$ 134,918	$ 163,666	$ 172,060	$ 163,795	$ 134,641	$ 658,875	$ 634,162	$ 610,811
Net income per limited partnership unit	$ 19.75	$ 19.94	$ 19.59	$ 15.26	$ 18.51	$ 19.47	$ 18.53	$ 15.23	$ 74.54	$ 71.74	$ 69.10