Summary of Significant Accounting Policies - Properties in Development (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
Total real estate assets	$ 11,101,858	$ 11,095,294
Other Cost and Expense, Operating	10,500	2,500	$ 1,900
Refundable deposits - development
Property Plant And Equipment [Line Items]
Nonrefundable deposits and other predevelopment costs	25,300	17,700
Parent Company [Member]
Property Plant And Equipment [Line Items]
Land	4,230,989	4,288,695
Land improvements	630,264	607,624
Buildings	5,083,660	5,101,061
Building and tenant improvements	997,704	946,034
Construction in progress	159,241	151,880
Total real estate assets	$ 11,101,858	$ 11,095,294