Equity Transactions (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Sep. 30, 2018
Class of Stock [Line Items]
Common stock, shares authorized	670,000,000	670,000,000
Proceeds from issuance from common stock	$ (296)	$ 72,539	$ (919)
Redemption value of operating partnership units outstanding	$ 544,800	$ 692,500
Operating Partnership
Class of Stock [Line Items]
General partner ownership interest	96.60%
ATM Program, 2018
Class of Stock [Line Items]
Common stock, shares authorized	826,600,000			900,000,000.0
Sale of common stock, net (in shares)		228,271
Share issued, price per share (in dollars per share)		$ 321.56
Proceeds from issuance from common stock		$ 73,400
Operating Partnership Units
Class of Stock [Line Items]
Number of shares outstanding	2,188,623	2,158,396
Long Term Incentive Plan 2014 Units
Class of Stock [Line Items]
Number of shares outstanding	106,137	143,257