New Issued Accounting Pronouncements (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($) capital_lease administrative_office center	Mar. 31, 2018 USD ($)	Jan. 01, 2019 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Real estate taxes, net	$ 16,131	$ 17,639
Number of properties with ground lease agreements | center	12
Number of administrative office leases | administrative_office	4
Number of capital leases | capital_lease	1
Finance Lease Assets, Number of Units, Centers | center	2
Finance lease obligations	$ 21,900
Operating leases, liabilities	$ 42,425
Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease, right-of-use asset			$ 44,200
Operating leases, liabilities			$ 42,900
Lease Arrangement, Lessor [Member] | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Real estate taxes, net		$ 1,200