Real Estate Intangibles

12 Months Ended

Dec. 31, 2010

4. Real Estate Intangibles

The following is a summary of our real estate intangibles, excluding those classified as held for sale, as of the dates indicated (dollars in thousands):


	December 31, 2010			December 31, 2009
Assets:
In place lease intangibles	$	182,030		$	74,198
Above market tenant leases		24,089			10,232
Below market ground leases		46,992			39,806
Lease commissions		4,968			3,154

Gross historical cost		258,079			127,390
Accumulated amortization		(49,145	)		(29,698	)

Net book value	$	208,934		$	97,692

Weighted-average amortization period in years		18.2			30.0

Liabilities:
Below market tenant leases	$	57,261		$	22,961
Above market ground leases		5,020			4,084

Gross historical cost		62,281			27,045
Accumulated amortization		(15,992	)		(10,478	)

Net book value	$	46,289		$	16,567

Weighted-average amortization period in years		14.0			12.1