Fair Value Measurements - Carrying Amounts and Estimated Fair Values by Input Level (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Jul. 01, 2021	Feb. 28, 2021	May 31, 2020	Jan. 19, 2017
Financial assets:
Equity securities	$ 10.6	$ 10.7
Senior Notes | 5.625% Notes due 2027
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate	5.625%					5.625%
Senior Notes | 4.125% Notes due 2029
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate	4.125%		4.125%
Convertible Notes
Financial liabilities:
Long-term debt	$ 31.5	24.2
Convertible Notes | Convertible Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate	2.75%				2.75%
Other long-term obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate				27.00%
Fair Value, Recurring | Level 1
Financial assets:
Cash and cash equivalents	$ 706.6	1,071.8
Equity securities	10.6	10.7
Available-for-sale debt securities	0.0	0.0
Held-to-maturity securities	0.0	0.0
Promissory notes	0.0	0.0
Financial liabilities:
Other liabilities	0.0	0.0
Fair Value, Recurring | Level 1 | Amended Credit Facilities
Financial liabilities:
Long-term debt	0.0	1,483.5
Fair Value, Recurring | Level 1 | Senior Notes | 5.625% Notes due 2027
Financial liabilities:
Long-term debt	0.0	388.0
Fair Value, Recurring | Level 1 | Senior Notes | 4.125% Notes due 2029
Financial liabilities:
Long-term debt	0.0	340.0
Fair Value, Recurring | Level 1 | Convertible Notes | Convertible Notes
Financial liabilities:
Long-term debt	0.0	427.6
Fair Value, Recurring | Level 1 | Other long-term obligations
Financial liabilities:
Long-term debt	0.0	0.0
Fair Value, Recurring | Level 2
Financial assets:
Cash and cash equivalents	0.0	0.0
Equity securities	0.0	0.0
Available-for-sale debt securities	0.0	0.0
Held-to-maturity securities	6.7	6.7
Promissory notes	7.9	7.9
Financial liabilities:
Other liabilities	2.7	2.7
Fair Value, Recurring | Level 2 | Amended Credit Facilities
Financial liabilities:
Long-term debt	1,453.9	0.0
Fair Value, Recurring | Level 2 | Senior Notes | 5.625% Notes due 2027
Financial liabilities:
Long-term debt	393.0	0.0
Fair Value, Recurring | Level 2 | Senior Notes | 4.125% Notes due 2029
Financial liabilities:
Long-term debt	356.0	0.0
Fair Value, Recurring | Level 2 | Convertible Notes | Convertible Notes
Financial liabilities:
Long-term debt	355.7	0.0
Fair Value, Recurring | Level 2 | Other long-term obligations
Financial liabilities:
Long-term debt	8.1	18.0
Fair Value, Recurring | Level 3
Financial assets:
Cash and cash equivalents	0.0	0.0
Equity securities	0.0	0.0
Available-for-sale debt securities	31.5	24.2
Held-to-maturity securities	0.0	0.0
Promissory notes	0.0	0.0
Financial liabilities:
Other liabilities	41.9	76.2
Fair Value, Recurring | Level 3 | Amended Credit Facilities
Financial liabilities:
Long-term debt	0.0	0.0
Fair Value, Recurring | Level 3 | Senior Notes | 5.625% Notes due 2027
Financial liabilities:
Long-term debt	0.0	0.0
Fair Value, Recurring | Level 3 | Senior Notes | 4.125% Notes due 2029
Financial liabilities:
Long-term debt	0.0	0.0
Fair Value, Recurring | Level 3 | Convertible Notes | Convertible Notes
Financial liabilities:
Long-term debt	0.0	0.0
Fair Value, Recurring | Level 3 | Other long-term obligations
Financial liabilities:
Long-term debt	201.2	154.1
Fair Value, Recurring | Carrying Amount
Financial assets:
Cash and cash equivalents	706.6	1,071.8
Equity securities	10.6	10.7
Available-for-sale debt securities	31.5	24.2
Held-to-maturity securities	6.7	6.7
Promissory notes	7.9	7.9
Financial liabilities:
Other liabilities	44.6	79.0
Fair Value, Recurring | Carrying Amount | Amended Credit Facilities
Financial liabilities:
Long-term debt	1,437.0	1,471.7
Fair Value, Recurring | Carrying Amount | Senior Notes | 5.625% Notes due 2027
Financial liabilities:
Long-term debt	399.8	399.7
Fair Value, Recurring | Carrying Amount | Senior Notes | 4.125% Notes due 2029
Financial liabilities:
Long-term debt	395.5	394.6
Fair Value, Recurring | Carrying Amount | Convertible Notes | Convertible Notes
Financial liabilities:
Long-term debt	327.9	326.1
Fair Value, Recurring | Carrying Amount | Other long-term obligations
Financial liabilities:
Long-term debt	210.5	173.5
Fair Value, Recurring | Fair Value
Financial assets:
Cash and cash equivalents	706.6	1,071.8
Equity securities	10.6	10.7
Available-for-sale debt securities	31.5	24.2
Held-to-maturity securities	6.7	6.7
Promissory notes	7.9	7.9
Financial liabilities:
Other liabilities	44.6	78.9
Fair Value, Recurring | Fair Value | Amended Credit Facilities
Financial liabilities:
Long-term debt	1,453.9	1,483.5
Fair Value, Recurring | Fair Value | Senior Notes | 5.625% Notes due 2027
Financial liabilities:
Long-term debt	393.0	388.0
Fair Value, Recurring | Fair Value | Senior Notes | 4.125% Notes due 2029
Financial liabilities:
Long-term debt	356.0	340.0
Fair Value, Recurring | Fair Value | Convertible Notes | Convertible Notes
Financial liabilities:
Long-term debt	355.7	427.6
Fair Value, Recurring | Fair Value | Other long-term obligations
Financial liabilities:
Long-term debt	$ 209.3	$ 172.1