CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Apr. 30, 2021	Dec. 31, 2019
1.75 Percent Convertible Senior Notes [Member]
Financing activities:
Interest rate on convertible senior notes	1.75%	1.75%
0.125 Percent Convertible Senior Notes [Member]
Financing activities:
Interest rate on convertible senior notes	0.125%	0.125%	0.125%		0.125%
Principal amount repurchased	$ 504.4
0 Percent Convertible Senior Notes [Member]
Financing activities:
Interest rate on convertible senior notes	0.00%	0.00%	0.00%	0.00%
1 Percent Convertible Senior Notes [Member]
Financing activities:
Interest rate on convertible senior notes	1.00%		1.00%
Principal amount repurchased			$ 247.9		$ 375.6