They had a lease on that building, as far as I know.
They paid $200 mln or so for redevelopment/reconstruction, lease was about $3 mln per year from what I read.
They took over in 2014 or so. $375 mln should at least break even, but I believe they sold for a profit even if not including the profits from running the hotel during these 6-7 yrs.
https://en.wikipedia.org/wiki/Old_Post_Office_(Washington%2C_D.C.)