Investment in 111 West 57th Partners LLC, Additional Information Regarding Equity Investment in 111 West 57th Property (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2014	Jun. 30, 2015
Additional Information Regarding Equity Investment in 111 West 57th Property [Abstract]
Description of partnership agreement distribution	The JV Agreement and related operating agreements generally provide that all distributable cash shall be distributed as follows: (i) first, 100% to the members in proportion to their percentage interests until Investment LLC has received distributions yielding a 20% internal rate of return as calculated; (ii) second, 100% to the Sponsor as a return of (but not a return on) any additional capital contributions made by the Sponsor on account of manager overruns; and (iii) thereafter, (a) 50% to the members in proportion to their respective percentage interests at the time of such distribution, and (b) 50% to the Sponsor.
Subordinated participation interest to CEO		10.00%
Percentage of distribution on company's initial investment to be received prior to CEO receiving percentage distribution		150.00%
Investment LLC [Member] | Capital LLC [Member]
Additional Information Regarding Equity Investment in 111 West 57th Property [Abstract]
Terms of distributions to Capital LLC	available cash of Investment LLC will be distributed first to Capital LLC until it has received a 20% internal rate of return (calculated as provided for in the JV Agreement as noted above), second to the Company until it has received 150% of its capital, and, thereafter, available cash is split 10/90, with 10% going to Mr. R. A. Bianco as the subordinated participation interest noted above and 90% going to Capital LLC and the Company pari-passu, with Capital LLC receiving one-half of its pro-rata share based on capital contributed and the Company receiving the balance.
AIG [Member]
Information Relating to Financing for Investment Property [Abstract]
Financing obtained by 111 W 57th Partners			$ 400,000
Apollo [Member]
Information Relating to Financing for Investment Property [Abstract]
Financing obtained by 111 W 57th Partners			$ 325,000