Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions		Sep. 30, 2020	Dec. 31, 2019
Assets
Accounts receivable (including $9.5 and $11.2 of related party)		$ 9.5	$ 11.2
Real estate and acquired in place lease values, net of accumulated depreciation and amortization		805.2	703.2
Unconsolidated investments (including $1,114.6 and $1,099.3 at fair value)		1,114.6	1,099.3
Assets	[1]	7,176.6	7,304.5
Real estate and acquired in place lease values (net of accumulated depreciation and amortization of $805.2 and $703.2)		4,786.7	5,080.2
Liabilities
Liabilities	[1]	$ 5,660.0	$ 5,585.3
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, par or stated value per share (in dollars per share)		$ 0.0001	$ 0.0001
Preferred stock, liquidation preference per share (in dollars per share)		$ 1,000	$ 1,000
Preferred stock, shares authorized (in shares)		1,000,000	1,000,000
Preferred stock, shares outstanding (in shares)		300,000	300,000
Common stock, par or stated value per share (in dollars per share)		$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)		200,000,000	200,000,000
Common stock, shares issued (in shares)		142,074,132	142,283,109
Common stock, shares outstanding (in shares)		142,074,132	142,283,109
Variable Interest Entity, Primary Beneficiary [Member]
Assets
Assets		$ 154.4	$ 267.5
Cash held by consolidated investments		7.3	10.3
Real estate and acquired in place lease values (net of accumulated depreciation and amortization of $805.2 and $703.2)		137.3	243.5
Liabilities
Liabilities		97.7	219.7
Variable Interest Entity, Primary Beneficiary [Member] | Investment Debt [Member]
Liabilities
Long-term debt		$ 88.8	$ 206.0

[1] The assets and liabilities as of September 30, 2020 include $154.4 million (including cash held by consolidated investments of $7.3 million and real estate and acquired in place lease values, net of accumulated depreciation and amortization of $137.3 million) and $97.7 million (including mortgage debt of $88.8 million), respectively, from consolidated variable interest entities ("VIEs"). The assets and liabilities as of December 31, 2019 include $267.5 million (including cash held by consolidated investments of $10.3 million and real estate and acquired in place lease values, net of accumulated depreciation and amortization of $243.5 million) and $219.7 million (including mortgage debt of $206.0 million), respectively, from VIEs. These assets can only be used to settle obligations of the consolidated VIEs, and the liabilities do not have recourse to the Company.