Stockholders' Equity and Partners' Capital - Narrative (Details) - USD ($)	3 Months Ended		41 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Dec. 31, 2019
Class Of Stock [Line Items]
Shares withheld for taxes	44,500
Shares withheld for taxes, value	$ 2,300,000
Gross proceeds from issuance of common stock	$ 17,677,000	$ 32,379,000
Preferred stock, shares outstanding	6,900,000		6,900,000	6,900,000
Dividend rate	6.00%
Liquidation value (in USD per share)	$ 25.00		$ 25.00
Dividend rate, quarterly basis (in USD per share)	0.375
Dividend rate, annual basis (in USD per share)	$ 1.50
ATM Program November2016
Class Of Stock [Line Items]
Common stock authorized	$ 500,000,000.0
Issuance of common shares	400,000		5,600,000
Gross proceeds from issuance of common stock	$ 17,900,000
Gross proceeds capacity remaining	$ 246,300,000		$ 246,300,000
ATM Program November2016 | Weighted Average
Class Of Stock [Line Items]
Share issued during the period (in dollars per share)	$ 49.30
ATM Program, Forward Sales
Class Of Stock [Line Items]
Issuance of common shares	400,000		3,800,000
Number of open forward sales agreements	0		0