Intangible Assets and Below Market Lease Liabilities - Scheduled Future Amortization (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2013	Dec. 31, 2012
Scheduled future amortization of intangible assets [Abstract]
Deferred financing and leasing costs, net/Total scheduled future amortization of intangible assets	$ 181,802	$ 181,802	$ 168,019
Deferred Financing Costs [Member]
Scheduled future amortization of intangible assets [Abstract]
July 1, 2013 through December 31, 2013	1,828	1,828
2014	3,241	3,241
2015	2,606	2,606
2016	1,508	1,508
2017	1,220	1,220
Thereafter	1,437	1,437
Deferred financing and leasing costs, net/Total scheduled future amortization of intangible assets	11,840	11,840	13,897
Weighted average remaining amortization periods for intangible assets and below market lease liabilities [Abstract]
Finite-lived intangible assets, average useful life (in years)		5 years 4 months 24 days
Deferred Leasing Costs and Acquisition-Related Intangible Assets [Member]
Scheduled future amortization of intangible assets [Abstract]
July 1, 2013 through December 31, 2013	17,283	17,283
2014	30,455	30,455
2015	24,935	24,935
2016	20,563	20,563
2017	17,526	17,526
Thereafter	41,368	41,368
Deferred financing and leasing costs, net/Total scheduled future amortization of intangible assets	152,130	152,130
Weighted average remaining amortization periods for intangible assets and below market lease liabilities [Abstract]
Finite-lived intangible assets, average useful life (in years)		6 years 4 months 24 days
Lease Incentives [Member]
Scheduled future amortization of intangible assets [Abstract]
July 1, 2013 through December 31, 2013	621	621
2014	1,160	1,160
2015	932	932
2016	738	738
2017	664	664
Thereafter	2,107	2,107
Deferred financing and leasing costs, net/Total scheduled future amortization of intangible assets	6,222	6,222
Weighted average remaining amortization periods for intangible assets and below market lease liabilities [Abstract]
Finite-lived intangible assets, average useful life (in years)		7 years 7 months 6 days
Acquisition-Related Intangible Assets (in Rental and Other Revenues) [Member]
Scheduled future amortization of intangible assets [Abstract]
July 1, 2013 through December 31, 2013	1,032	1,032
2014	1,817	1,817
2015	1,438	1,438
2016	1,085	1,085
2017	951	951
Thereafter	1,156	1,156
Deferred financing and leasing costs, net/Total scheduled future amortization of intangible assets	7,479	7,479
Weighted average remaining amortization periods for intangible assets and below market lease liabilities [Abstract]
Finite-lived intangible assets, average useful life (in years)		5 years 1 month 6 days
Acquired finite-lived intangible assets, average useful life (in years)	4 years 2 months 12 days
Acquisition-Related Intangible Assets (in Rental Property and Other Expenses) [Member]
Scheduled future amortization of intangible assets [Abstract]
July 1, 2013 through December 31, 2013	277	277
2014	553	553
2015	553	553
2016	553	553
2017	553	553
Thereafter	1,642	1,642
Deferred financing and leasing costs, net/Total scheduled future amortization of intangible assets	4,131	4,131
Weighted average remaining amortization periods for intangible assets and below market lease liabilities [Abstract]
Finite-lived intangible assets, average useful life (in years)		8 years
Acquisition-Related Below Market Lease Liabilities [Member]
Scheduled future amortization of below market lease liabilities [Abstract]
July 1, 2013 through December 31, 2013	(2,856)	(2,856)
2014	(5,080)	(5,080)
2015	(4,367)	(4,367)
2016	(4,293)	(4,293)
2017	(4,037)	(4,037)
Thereafter	(19,432)	(19,432)
Total scheduled future amortization of acquisition-related below market lease liabilities	$ (40,065)	$ (40,065)	$ (33,636)
Weighted average remaining amortization periods for intangible assets and below market lease liabilities [Abstract]
Finite-lived below market lease liabilities, average useful life (in years)		9 years 2 months 12 days
Assumed finite-lived below market lease liabilities, average useful life (in years)	7 years 6 months
in-Place Lease Intangible Assets [Member]
Weighted average remaining amortization periods for intangible assets and below market lease liabilities [Abstract]
Acquired finite-lived intangible assets, average useful life (in years)	5 years 3 months 18 days