Assets and Liabilities Measured at Fair Value - Narratives (Details)	12 Months Ended
	Dec. 31, 2020 USD ($) OffsettingPosition	Dec. 31, 2019 USD ($) OffsettingPosition	Dec. 31, 2018 USD ($)
Expected life	2 years
Number of offsetting positions (in offsetting positions) | OffsettingPosition	0	0
Impairment of assets | $	$ 1,206,284,000	$ 0	$ 20,000,000
Contingent consideration
Expected life	5 years
Fair value, expected volatility rate	9.90%
Risk-free interest rate	0.68%