Income Taxes	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income TaxesIn calculating the provision for income taxes, the Company uses an estimate of the annual effective tax rate based upon the facts and circumstances at each interim period. On a quarterly basis, the estimated annual effective tax rate is adjusted, as appropriate, based upon changes in facts and circumstances, if any, as compared to those forecasted at the beginning of the fiscal year and at each interim period thereafter.The provision for income taxes reflected U.S. federal, state and local taxes at an estimated effective tax rate of 24.0% and 33.9% for the nine months ended September 30, 2021 and 2020, respectively. The comparatively lower estimated effective tax rate for the nine months ended September 30, 2021 was primarily due to valuation allowances recorded in the prior year period for the tax effects of unrealized losses on certain Company investments.