Accounts payable, accrued expenses and tenant security deposits (Notes)

3 Months Ended

Mar. 31, 2015

Accounts payable, accrued expenses, and tenant security deposits [Abstract]

Schedule of Accounts Payable and Accrued Liabilities [Table Text Block]

Accounts payable, accrued expenses, and tenant security deposits

The following table summarizes the components of accounts payable, accrued expenses, and tenant security deposits as of March 31, 2015, and December 31, 2014 (in thousands):



	March 31,		December 31
	2015		2014
Accounts payable and accrued expenses	$	156,269	$	127,828
Accrued construction	85,769		91,110
Acquired below market leases	29,198		8,810
Conditional asset retirement obligations	8,984		9,108
Deferred rent liabilities	26,722		36,231
Interest rate swap liabilities	3,417		909
Prepaid rent and tenant security deposits	204,688		193,699
Other liabilities ⁽¹⁾	130,572		21,390
Total	$	645,619	$	489,085

(1)

Our March 31, 2015, balance includes a noncontrolling interest purchase liability related to the $108.3 million acquisition of the outstanding 10% noncontrolling interest in our 1.2 million RSF, flagship campus at Alexandria Technology Square^®. For additional information, refer to Note 11 – “Noncontrolling Interests” to our unaudited consolidated financial statements under Item 1 of this report.