Supplemental Disclosure to Statements of Cash Flows (Tables)

6 Months Ended

Jun. 30, 2013

Supplemental Disclosure to Statements of Cash Flows [Abstract]

Supplemental Disclosure to Statements of Cash Flows

	2013		2012
Write-off of fully depreciated property and deferred costs	$	17,784	$	12,783
Write-off of depreciated property and deferred costs due to sale	$	49,618	$	94,762
Write-off of origination costs relating to preferred unit redemptions	$	1,236	$	2,811