CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024
Statement of Cash Flows [Abstract]
Net income	$ 136.1	$ 109.4
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	66.0	66.4
Share-based compensation	25.0	22.7
Unrealized foreign exchange loss, net	23.8	11.0
Deferred income taxes	(26.6)	6.9
Amortization of debt issuance costs	1.6	2.0
Changes in working capital, net of amounts acquired:
Income taxes payable, net	2.2	0.5
Trade accounts receivable, including amounts in settlement assets	80.8	56.7
Prepaid expenses and other current assets, including amounts in settlement assets	(30.3)	112.8
Trade accounts payable, including amounts in settlement obligations	(159.7)	(121.9)
Deferred revenue	(4.3)	(0.1)
Accrued expenses and other current liabilities, including amounts in settlement obligations	86.0	(55.3)
Changes in noncurrent assets and liabilities	(16.0)	1.1
Net cash provided by operating activities	184.6	212.2
Cash flows from investing activities:
Acquisitions, net of cash acquired	3.2	(90.8)
Issuance of convertible notes receivable	(25.0)
Purchases and proceeds of property and equipment	(57.8)	(57.2)
Purchases of other long-term assets	(7.1)	(6.6)
Other, net	(2.2)	(0.6)
Net cash used in investing activities	(88.9)	(155.2)
Cash flows from financing activities:
Proceeds from issuance of shares	3.5	3.3
Repurchase of shares	(310.6)	(116.3)
Borrowings from credit agreements	4,848.0	3,990.8
Repayments of credit agreements	(4,404.0)	(4,131.1)
Repayment of convertible notes	(491.8)
Repayments of capital lease obligations	(0.7)	(1.0)
Net borrowing from short-term debt obligations	434.8	558.7
Net cash provided by financing activities	79.2	304.4
Effect of exchange rate changes on cash and cash equivalents and restricted cash	257.8	(53.2)
Increase in cash and cash equivalents and restricted cash	432.7	308.2
Cash and cash equivalents and restricted cash at beginning of period	2,488.2	2,247.0
Cash and cash equivalents and restricted cash at end of period	2,920.9	2,555.2
Supplemental disclosure of cash flow information:
Interest paid during the period	33.3	29.5
Income taxes paid during the period	$ 74.7	$ 52.1