Supplemental Disclosure to Statements of Cash Flows (Tables)

6 Months Ended

Jun. 30, 2012

Supplemental Disclosure to Statements of Cash Flows [Abstract]

Supplemental Disclosure to Statements of Cash Flows

	2012		2011
Write-off of fully depreciated property and deferred costs	$	12,783	$	9,595
Write-off of depreciated property and deferred costs due to sale	$	94,762	$	90,087
Write-off of origination costs relating to preferred unit redemptions	$	2,811	$	—