Income Taxes	6 Months Ended
	Jun. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income TaxesWe determine the tax provision for interim periods using an estimate of our annual effective tax rate, adjusted for discrete items, if any, that are taken into account in the relevant period. Each quarter we update our estimate of the annual effective tax rate, and if our estimated tax rate changes, we make a cumulative adjustment. Our effective tax rate was 23.3% and 20.7% for the first six months of 2021 and 2020, respectively. A $6 million valuation allowance was recorded in the second quarter of 2021 against a deferred tax asset where it became more likely than not that such deferred tax asset will not be realized, while a valuation allowance of $3 million was recorded during the first quarter of 2020. The remainder of the increase in the effective tax rate is primarily related to unfavorability of permanent book-tax differences for share-based compensation in 2021 compared to 2020.