Investments - Schedule of Loans Receivable, Net of Premium and Allowance for Loan Losses (Details) - USD ($) $ in Thousands |
Jun. 30, 2019 |
Dec. 31, 2018 |
|---|---|---|
| Loans and Leases Receivable Disclosure [Line Items] | ||
| Loans and leases receivable, gross | $ 36,707 | $ 44,742 |
| Total loans receivable, net | 38,220 | 47,044 |
| Mortgage Loans | ||
| Loans and Leases Receivable Disclosure [Line Items] | ||
| Loans and leases receivable, gross | 34,681 | 42,660 |
| Mortgage loans - premiums, net of amortization | 1,706 | 2,527 |
| Allowance for loan losses | 0 | 0 |
| Total loans receivable, net | 36,387 | 45,187 |
| Other Notes Receivable | ||
| Loans and Leases Receivable Disclosure [Line Items] | ||
| Loans and leases receivable, gross | 2,026 | 2,082 |
| Mortgage loans - premiums, net of amortization | (193) | (225) |
| Allowance for loan losses | 0 | 0 |
| Total loans receivable, net | $ 1,833 | $ 1,857 |