Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions		Mar. 31, 2020	Dec. 31, 2019
Assets
Related party accounts receivable		$ 10.1	$ 11.2
Fair value of unconsolidated investments		1,081.6	1,107.4
Assets	[1]	6,948.0	7,304.5
Real estate and acquired in place lease values (net of accumulated depreciation and amortization of $706.3 and $703.2)		4,715.8	5,080.2
Real estate and acquired in place lease values, net of accumulated depreciation and amortization		706.3	703.2
Liabilities
Liabilities	[1]	$ 5,293.0	$ 5,585.3
Stockholders' Equity Attributable to Parent [Abstract]
Cumulative preferred Stock, par value (in dollars per share)		$ 0.0001	$ 0.0001
Cumulative preferred Stock, shares authorized (in shares)		1,000,000	1,000,000
Cumulative preferred Stock, shares outstanding (in shares)		300,000	300,000
Cumulative preferred stock, liquidation preference (in dollars per share)		$ 1,000	$ 1,000
Common stock, par value (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)		143,548,864	142,283,109
Common stock, shares outstanding (in shares)		143,548,864	142,283,109
Variable Interest Entity, Primary Beneficiary [Member]
Assets
Assets		$ 136.3	$ 267.5
Cash held by consolidated investments		4.5	10.3
Real estate and acquired in place lease values (net of accumulated depreciation and amortization of $706.3 and $703.2)		122.9	243.5
Liabilities
Liabilities		84.4	219.7
Variable Interest Entity, Primary Beneficiary [Member] | Investment Debt [Member]
Liabilities
Long-term debt		$ 78.6	$ 206.0

[1] The assets and liabilities as of March 31, 2020 include $136.3 million (including cash held by consolidated investments of $4.5 million and real estate and acquired in place lease values, net of accumulated depreciation and amortization of $122.9 million) and $84.4 million (including investment debt of $78.6 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 investment 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.