Real Estate Intangibles

3 Months Ended

Jun. 30, 2013

Real Estate Intangibles [Abstract]

Real Estate Intangibles

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):

		June 30, 2013		December 31, 2012
Assets:
	In place lease intangibles	$	797,343	$	541,729
	Above market tenant leases		54,238		56,086
	Below market ground leases		61,461		61,450
	Lease commissions		15,868		14,419
	Gross historical cost		928,910		673,684
	Accumulated amortization		(375,767)		(257,242)
	Net book value	$	553,143	$	416,442
	Weighted-average amortization period in years		17.6		16.4
Liabilities:
	Below market tenant leases	$	76,968	$	77,036
	Above market ground leases		9,490		9,490
	Gross historical cost		86,458		86,526
	Accumulated amortization		(31,580)		(27,753)
	Net book value	$	54,878	$	58,773
	Weighted-average amortization period in years		14.3		14.3

The following is a summary of real estate intangible amortization for the periods presented (in thousands):

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2013		2012		2013		2012
Rental income related to above/below market tenant leases, net	$	213	$	282	$	361	$	887
Property operating expenses related to above/below market ground leases, net		(303)		(347)		(606)		(647)
Depreciation and amortization related to in place lease intangibles and lease commissions		(39,083)		(28,551)		(89,659)		(55,843)

     The future estimated aggregate amortization of intangible assets and liabilities is as follows for the periods presented (in thousands):

		Assets		Liabilities
2013	$	142,493	$	3,523
2014		151,663		6,644
2015		46,355		5,659
2016		23,954		5,247
2017		23,612		4,928
Thereafter		165,066		28,877
Totals	$	553,143	$	54,878