Supplemental Cash Flow Information of the Company - Supplemental Cash Flow (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Jan. 01, 2019
SUPPLEMENTAL CASH FLOWS INFORMATION:
Cash paid for interest, net of capitalized interest of $18,901 and $13,051 as of March 31, 2019 and 2018, respectively	$ 4,706	$ 9,699
Capitalized interest	18,901	13,051
Cash paid for amounts included in the measurement of ground lease liabilities	1,220	1,239
NON-CASH INVESTING TRANSACTIONS:
Accrual for expenditures for operating properties and development properties	87,038	57,155
Tenant improvements funded directly by tenants	2,682	2,014
Operating right of use ground lease asset	82,794		$ 82,938
Operating ground lease liabilities	87,247		$ 87,409
NON-CASH FINANCING TRANSACTIONS:
Accrual of dividends and distributions payable to common stockholders and common unitholders	47,676	43,512
Exchange of common units of the Operating Partnership into shares of the Company’s common stock	$ 78	$ 244