CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	197,900,000	197,900,000
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Redeemable Preferred Stock [Member] | Series B [Member]
Preferred Stock, Dividend Rate, Percentage	6.00%	6.00%
Temporary Equity, Liquidation Preference Per Share	$ 1,000	$ 1,000
Temporary Equity, Shares Authorized	1,225,000	1,225,000
Temporary Equity, Shares Issued	516,100	536,695
Temporary Equity, Shares Outstanding	516,100	536,695
Redeemable Preferred Stock [Member] | Series T
Preferred Stock, Dividend Rate, Percentage	6.15%	6.15%
Temporary Equity, Liquidation Preference Per Share	$ 25.00	$ 25.00
Temporary Equity, Shares Authorized	32,000,000	32,000,000
Temporary Equity, Shares Issued	6,671,458	17,400
Temporary Equity, Shares Outstanding	6,671,458	17,400
Cumulative Redeemable Preferred Stock | Series A [Member]
Preferred Stock, Dividend Rate, Percentage	8.25%	8.25%
Temporary Equity, Liquidation Preference Per Share	$ 25.00	$ 25.00
Temporary Equity, Shares Authorized	10,875,000	10,875,000
Temporary Equity, Shares Issued	5,558,392	5,721,460
Temporary Equity, Shares Outstanding	5,558,392	5,721,460
Cumulative Redeemable Preferred Stock | Series C [Member]
Preferred Stock, Dividend Rate, Percentage	7.625%	7.625%
Temporary Equity, Liquidation Preference Per Share	$ 25.00	$ 25.00
Temporary Equity, Shares Authorized	4,000,000	4,000,000
Temporary Equity, Shares Issued	2,295,845	2,323,750
Temporary Equity, Shares Outstanding	2,295,845	2,323,750
Cumulative Redeemable Preferred Stock | Series D [Member]
Preferred Stock, Liquidation Preference Per Share	$ 25.00	$ 25.00
Preferred Stock, Shares Authorized	4,000,000	4,000,000
Preferred Stock, Shares Issued	2,774,338	2,850,602
Preferred Stock, Shares Outstanding	2,774,338	2,850,602
Preferred Stock, Dividend Rate, Percentage	7.125%	7.125%
Class A Common Stock [Member]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	747,509,582	747,509,582
Common stock, shares issued	24,589,389	23,422,557
Common stock, shares outstanding	24,589,389	23,422,557
Class C Common Stock [Member]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	76,603	76,603
Common stock, shares issued	76,603	76,603
Common stock, shares outstanding	76,603	76,603