Earnings Per Common Share - Schedule of Calculation of Numerator and Denominator in Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Numerators:
Net income available to Common Stockholders—Basic	$ 228,268	$ 279,123	$ 212,596
Amounts allocated to dilutive securities	13,132	16,783	13,774
Net income available to Common Stockholders—Fully Diluted	$ 241,400	$ 295,906	$ 226,370
Denominator:
Weighted average Common Shares outstanding – Basic (shares)	181,828	180,805	177,928
Effect of dilutive securities:
Exchange of Common OP Units for Common Shares (shares)	10,484	10,934	11,586
Stock options and restricted stock (shares)	243	256	596
Weighted average Common Shares outstanding – Fully Diluted (shares)	192,555	191,995	190,110
Earnings per Common Share – Basic (usd per share)	$ 1.26	$ 1.54	$ 1.19
Earnings per Common Share – Fully Diluted (usd per share)	$ 1.25	$ 1.54	$ 1.19