CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Residential mortgage loans, held-for-investment, fair value	$ 121,088	$ 0
Notes and bonds payable, fair value	$ 117,048	$ 0
Equity
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	2,000,000,000	2,000,000,000
Common stock, shares issued (in shares)	369,104,429	307,361,309
Common stock, shares outstanding (in shares)	369,104,429	307,361,309