Acquired Intangible Assets, Amortization Expense (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Amortization of acquired intangible assets [Abstract]
Amortization expense	$ 2.1	$ 2.1
Estimated amortization expense, remainder of 2022	6.5
Estimated amortization expense in year 2023	8.3
Estimated amortization expense in year 2024	8.3
Estimated amortization expense in year 2025	8.3
Estimated amortization expense in years 2026 through 2041	$ 69.1