Results by Quarter (Tables)

12 Months Ended

Dec. 31, 2014

Quarterly Financial Information Disclosure [Abstract]

Summary of Results by Quarter

	First Quarter		Second Quarter		Third Quarter		Fourth Quarter
Year ended December 31, 2014
Rental revenues	$	189,699	$	199,422	$	207,297	$	209,275
Net income		142,722		177,911		178,597		178,296
Net income per limited partnership unit		16.15		20.13		20.20		20.17
Year ended December 31, 2013
Rental revenues	$	181,021	$	194,907	$	195,130	$	195,376
Net income		134,918		173,203		176,260		174,494
Net income per limited partnership unit		15.26		19.59		19.94		19.75