Results By Quarter (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2012

Schedule of Quarterly Financial Information

	First Quarter		Second Quarter		Third Quarter		Fourth Quarter
Year ended December 31, 2012
Rental revenues	$	236,295	$	245,626	$	255,739	$	248,010
Net income		177,266		207,261		222,787		215,877
Net income per limited partnership unit		3.71		4.34		4.67		4.52
Year ended December 31, 2011
Rental revenues	$	250,437	$	254,923	$	254,668	$	245,627
Net income		190,699		222,043		185,561		735,705
Net income per limited partnership unit		3.99		4.65		3.89		15.41