Fair Value Measurements - Schedule of Change in Restricted Investments Valued Using Level 3 Inputs (Details) - Fair Value Recurring Basis $ in Thousands	9 Months Ended
	Sep. 30, 2020 USD ($)
Fair Value, Assets
Investments, beginning balance	$ 42,000
Other liabilities, ending balance	4,000
Investments, ending balance	43,000
Fair Value, Inputs, Level 3
Fair Value, Assets
Investments, beginning balance	29,000
Other liabilities, ending balance	4,000
Investments, ending balance	50,000
Other Liabilities | Fair Value, Inputs, Level 3
Fair Value, Assets
Other liabilities, beginning balance	0
Value of additional investment received	2,000
Unrealized gain	2,000
Other liabilities, ending balance	4,000
Restricted Cash and Investments | Fair Value, Inputs, Level 3
Fair Value, Assets
Investments, beginning balance	29,000
Value of additional investment received	5,000
Unrealized gain	16,000
Investments, ending balance	$ 50,000