Loans Receivable - Allowance For Credit Loss (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for expected credit losses, beginning of period	$ 4,198	$ 3,928	$ 5,437	$ 2,146
Cumulative effect adjustment resulting from changes in accounting principles	1,970	8,719	1,970	8,719
Provision for expected credit losses	(2,228)	4,791	(3,467)	6,930
Allowance for expected credit losses, end of period	1,970	8,719	1,970	8,719
Cumulative effect adjustment resulting from changes in accounting principles
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for expected credit losses, beginning of period			0	(357)
Cumulative effect adjustment resulting from changes in accounting principles
Real estate loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for expected credit losses, beginning of period	1,608	1,435	1,683	1,502
Cumulative effect adjustment resulting from changes in accounting principles	1,501	4,318	1,501	4,318
Provision for expected credit losses	(107)	2,883	(182)	3,721
Allowance for expected credit losses, end of period	1,501	4,318	1,501	4,318
Real estate loans | Cumulative effect adjustment resulting from changes in accounting principles
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for expected credit losses, beginning of period			0	(905)
Cumulative effect adjustment resulting from changes in accounting principles
Commercial loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for expected credit losses, beginning of period	2,590	2,493	3,754	644
Cumulative effect adjustment resulting from changes in accounting principles	469	4,401	469	4,401
Provision for expected credit losses	(2,121)	1,908	(3,285)	3,209
Allowance for expected credit losses, end of period	$ 469	$ 4,401	469	4,401
Commercial loans | Cumulative effect adjustment resulting from changes in accounting principles
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for expected credit losses, beginning of period			$ 0	$ 548
Cumulative effect adjustment resulting from changes in accounting principles