AIR Equity (Details Textual)				12 Months Ended
	Jan. 28, 2021 $ / shares	Nov. 30, 2020 USD ($) shares	Feb. 03, 2019 USD ($) shares	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares	Dec. 14, 2020 shares
Class Of Stock [Line Items]
Common Stock, shares authorized (in shares)				1,021,175,000	500,787,260		1,021,175,000
Preferred Stock, shares authorized (in shares)							1,000,000
Dividends declared per common share (in dollars per share) | $ / shares				$ 40.12	$ 3.19	$ 1.52
Quarterly cash dividend amount (in dollars per share) | $ / shares				$ 0.82	$ 0.39
Equity reverse stock split		0.0123821	0.0103119
Classes of perpetual preferred stock
Cash dividends on common stock declared | $				$ 304,992,000	$ 241,643,000	$ 238,067,000
Preferred Stock, Liquidation Preference, Value | $				$ 100,000.0
Dividends per share percentage increase				8.5
Class A Cumulative Preferred Stock
Classes of perpetual preferred stock
Preferred stock, shares issued				20
Preferred stock, shares outstanding				20
Outstanding principal balance of shares issued and outstanding | $				$ 2,000,000.0
Preferred Stock, Par or Stated Value Per Share | $ / shares				$ 0.01
Special Dividend Paid [Member]
Classes of perpetual preferred stock
Cash dividends on common stock declared | $		$ 121,800,000	$ 67,100,000
Common shares issued in special dividend (in shares)		35,400,000	4,500,000
Special dividend, cash paid in lieu of fractional shares | $			$ 400,000
Special Dividend Paid [Member] | Subsequent Event [Member]
Class Of Stock [Line Items]
Quarterly cash dividend amount (in dollars per share) | $ / shares	$ 0.43
Common Stock
Class Of Stock [Line Items]
Dividends declared per common share (in dollars per share) | $ / shares				$ 0.41	$ 0.39	$ 0.38
Classes of perpetual preferred stock
Common shares issued in special dividend (in shares)				(28,629,000)	(3,628,000)