Intangibles Lease Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Intangibles
Gross intangible lease liabilities	$ 163,924	$ 155,883
Accumulated depreciation and amortization	(105,779)	(99,736)
Net intangible lease liabilities	$ 58,145	$ 56,147
Approximate remaining weighted-average amortization period of unfavorable market lease intangibles	11 years	10 years
Additional revenues from the amortization of net below market lease intangibles included in rental income	$ 4,000	$ 4,000	$ 3,000
Additional expense from the amortization of net below market ground lease intangibles included in operating expenses	1,000	1,000	1,000
Additional expense from the amortization of lease-up and non-compete agreement intangibles included in depreciation and amortization expense	$ 85,000	$ 76,000	$ 60,000