Exchangeable Redeemable Preferred Stock Conversion (Details) $ / shares in Units, $ in Millions				3 Months Ended		9 Months Ended	12 Months Ended		24 Months Ended
	Nov. 23, 2020 USD ($) $ / shares shares	Nov. 19, 2020 USD ($) $ / shares	Nov. 30, 1998 shares	Sep. 30, 2020 USD ($)	Jun. 30, 2006 USD ($)	Sep. 30, 2020 USD ($)	Dec. 31, 1991 $ / shares shares	Dec. 31, 1990 $ / shares shares	Dec. 31, 1991 $ / shares
Exchangeable Redeemable Preferred Stock
Class of Stock [Line Items]
Liquidation value in cash transaction in condition 1	0.90
Liquidation value amount as per cash transaction in condition 2	0.85
Liquidation value in issuance of shares common stock in condition 1	0.90
Liquidation value in issuance of shares common stock in condition 2	0.15
Number of fractional shares (in shares) | shares	0
Conversion per share amount (in dollars per share) | $ / shares		$ 10
Conversion of stock, amount converted		$ 142.3
Conversion of preferred stock to common stock	$ 108.9
Number of shares stock holder received (in shares) | shares	1,100,000
Preferred stock, redemption price per share (in dollars per share) | $ / shares	$ 17
Conversion of stock, amount issued	$ 19.2
Preferred stock redemption costs	0.2
Gain (loss) on extinguishment of debt	$ 14.0
Public Preferred Stock
Class of Stock [Line Items]
Preferred stock authorized (in shares) | shares								6,000,000
Preferred stock par value (in dollars per share) | $ / shares								$ 0.01
Preferred stock, shares issued (in shares) | shares								2,858,723
Adjusted accrued accretion of public preferred stock					$ 1.5
Preferred stock dividends (in shares) | shares							736,863	736,863
Redemption of public preferred stock (in shares) | shares			410,000
Preferred stock dividend rate per annum							6.00%	6.00%	12.00%
Preferred stock dividend rate per annum (in dollars per share) | $ / shares							$ 0.60	$ 0.60	$ 1.20
Preferred stock, liquidation preference (in dollars per share) | $ / shares							$ 10		$ 10
Dividends on preferred stock				$ 1.0		$ 2.9