CONSOLIDATED STATEMENTS OF CASH FLOWS $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Cash flows from operating activities:
Net income	$ 346.2	$ 241.7	$ 206.9
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	104.7	100.0	101.7
Amortization	4.4	3.4	2.7
Stock-based compensation	34.0	24.4	15.1
Non-cash restructuring charges	0.0	2.3	2.2
Pension settlement charge	3.7	3.5	0.0
Contingent consideration payments in excess of acquisition-date liability	(0.9)	(0.5)	(0.6)
Fixed asset impairments and sale of equipment, net	7.7	0.8	1.8
Deferred income taxes	(5.8)	15.3	0.9
Pension and other retirement plans, net	4.6	(2.6)	(7.9)
Equity in undistributed earnings of affiliates, net of dividends	(15.8)	(6.7)	(5.9)
Changes in assets and liabilities:
Increase in accounts receivable	(46.6)	(33.3)	(43.8)
Increase in inventories	(73.7)	(18.6)	(7.0)
Decrease (increase) in other current assets	5.5	2.6	(6.2)
Increase in accounts payable	36.6	25.3	0.4
Changes in other assets and liabilities	67.9	9.6	28.3
Net cash provided by operating activities	472.5	367.2	288.6
Cash flows from investing activities:
Capital expenditures	(174.4)	(126.4)	(104.7)
Purchase of investment in affiliated companies	0.0	(85.1)	0.0
Acquisition of business	0.0	(18.9)	0.0
Other, net	(5.1)	2.4	3.9
Net cash used in investing activities	(179.5)	(228.0)	(100.8)
Cash flows from financing activities:
Borrowings under revolving credit agreements	0.0	108.5	0.0
Repayments under revolving credit agreements	0.0	(136.3)	0.0
Issuance of long-term debt	0.0	90.0	0.0
Debt issuance cost	0.0	(1.2)	0.0
Repayments of long-term debt	(2.3)	(0.1)	(0.1)
Dividend payments	(48.1)	(45.1)	(42.1)
Proceeds from stock-based compensation awards	22.4	25.1	27.4
Employee stock purchase plan contributions	6.4	5.4	4.9
Shares purchased under share repurchase programs	(115.5)	(83.1)	(70.8)
Net cash used in financing activities	(137.1)	(36.8)	(80.7)
Effect of exchange rates on cash	20.5	(0.7)	(5.6)
Net increase in cash and cash equivalents	176.4	101.7	101.5
Cash, including cash equivalents at beginning of period	439.1	337.4	235.9
Cash, including cash equivalents at end of period	615.5	439.1	337.4
Supplemental cash flow information:
Interest paid, net of amounts capitalized	8.1	8.6	8.4
Income taxes paid, net	48.4	47.5	42.0
Accrued capital expenditures	31.3	17.0	15.0
Dividends declared, not paid	12.6	11.8	11.3
Purchase of investment in affiliated companies, treasury stock	$ 0.0	$ 4.9	$ 0.0