CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash Flows from Operating Activities
Net income	$ 169.0	$ 212.5
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	74.6	64.8
Stock-based compensation	33.7	35.9
Other	9.3	6.8
Changes in operating assets and liabilities, net of effects of acquisitions and divestiture:
Accounts receivable	48.1	(154.2)
Prepaid expenses and income taxes	14.5	26.4
Accounts payable	(2.5)	10.0
Accrued payroll	(34.8)	20.0
Income taxes payable	31.6	15.1
Other	(3.0)	(4.8)
Net cash provided by operating activities	340.5	232.5
Cash Flows from Investing Activities
Cash paid for property and equipment	(32.7)	(27.0)
Cash paid for acquisitions, net of cash acquired	0.0	351.8
Cash received from the sale of a business	0.0	9.8
Other	(0.6)	2.4
Net cash used in investing activities	(33.3)	(366.6)
Cash Flows from Financing Activities
Proceeds from long term debt	571.8	46.0
Principal payments of long term debt	(595.3)	0.0
Debt issuance and amendment costs	(8.6)	0.0
Proceeds from employee stock purchase plan	18.9	18.9
Repurchases of common stock	(197.7)	(227.6)
Payment of employment taxes related to release of restricted stock awards	(15.7)	(12.9)
Payment of contingent consideration	(5.0)	(8.1)
Net cash used in financing activities	(231.6)	(183.7)
Effect of exchange rate changes on cash and cash equivalents	(0.3)	(0.6)
Net increase (decrease) in cash and cash equivalents	75.3	(318.4)
Cash and cash equivalents at beginning of year	70.3	529.6
Cash and cash equivalents at end of period	145.6	211.2
Supplemental Disclosure of Cash Flow Information
Income taxes	12.0	33.4
Interest	39.4	23.6
Operating leases	20.0	20.4
Noncash transactions —
Operating lease right of use assets obtained in exchange for operating lease liabilities	$ 26.9	$ 15.5