Segment Reporting - Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Segment reporting
Total assets	$ 7,542,706	$ 6,476,424
Operating Segments | Office Portfolio
Segment reporting
Total assets	3,072,160	3,092,289
Operating Segments | SHOP
Segment reporting
Total assets	2,908,334	2,912,570
Non-Segment
Segment reporting
Total assets	$ 1,562,212	$ 471,565