Accumulated Other Comprehensive Income (Loss) (Tables)

12 Months Ended

Dec. 31, 2020

Equity [Abstract]

Summary of Components of AOCI

Accumulated other comprehensive income (loss) includes foreign currency translation adjustments from those subsidiaries not using the U.S. dollar as their functional currency, the cumulative gains and losses of derivative instruments that qualify as cash flow hedges, and the cumulative unrealized gains and losses of marketable securities. The following table provides a roll forward of accumulated other comprehensive income (loss) for the years ended December 31, 2020, 2019 and 2018 (in millions):

	Foreign Currency Translation			Marketable Securities			Total
Accumulated other comprehensive income (loss) as of January 1, 2018	$	(0.1	)	$	—		$	(0.1	)
Other comprehensive income (loss)		(0.3	)		(1.3	)		(1.6	)
Income tax (expense) benefit		—			0.3			0.3
Other comprehensive income (loss), net of tax		(0.3	)		(1.0	)		(1.3	)
Accumulated other comprehensive income (loss) as of December 31, 2018		(0.4	)		(1.0	)		(1.4	)
Other comprehensive income (loss)		(0.1	)		1.9			1.8
Income tax (expense) benefit		—			(0.5	)		(0.5	)
Other comprehensive income (loss), net of tax		(0.1	)		1.4			1.3
Accumulated other comprehensive income (loss) as of December 31, 2019		(0.5	)		0.4			(0.1	)
Other comprehensive income (loss)		(0.9	)		—			(0.9	)
Income tax (expense) benefit		—			—			—
Other comprehensive income (loss), net of tax		(0.9	)		—			(0.9	)
Accumulated other comprehensive income (loss) as of December 31, 2020	$	(1.4	)	$	0.4		$	(1.0	)