Investments - Offsetting of Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Asset derivatives:
Net Amounts of Assets/ Liabilities Presented in the Consolidated Balance Sheets	$ 10,793	$ 13,239
Free-standing derivatives
Asset derivatives:
Gross Amounts	10,793	13,239
Gross Amounts Offset in the Consolidated Balance Sheets	0	0
Net Amounts of Assets/ Liabilities Presented in the Consolidated Balance Sheets	10,793	13,239
Gross Amounts Not Offset in the Consolidated Balance Sheets, Financial Instruments	7,952	7,687
Gross Amounts Not Offset in the Consolidated Balance Sheets, Cash Collateral Received	1,960	6,640
Net Amount	$ 881	$ (1,088)