Quarterly Operating and Per Share Data (Unaudited) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Proprietary Products	$ 580,200,000	$ 548,000,000.0	$ 527,200,000	$ 491,500,000	$ 470,600,000	$ 456,100,000	$ 469,700,000	$ 443,500,000	$ 2,146,900,000	$ 1,839,900,000	$ 1,717,400,000
Gross profit	211,100,000	194,600,000	195,100,000	167,000,000.0	153,200,000	147,800,000	157,900,000	146,800,000	767,800,000	605,700,000	545,400,000
Net income	$ 98,400,000	$ 82,300,000	$ 91,200,000	$ 74,300,000	$ 63,900,000	$ 56,300,000	$ 66,100,000	$ 55,400,000	$ 346,200,000	$ 241,700,000	$ 206,900,000
Basic (in dollars per share)	$ 1.32	$ 1.11	$ 1.24	$ 1.01	$ 0.86	$ 0.76	$ 0.90	$ 0.75	$ 4.68	$ 3.27	$ 2.80
Diluted (in dollars per share)	$ 1.29	$ 1.09	$ 1.21	$ 0.99	$ 0.84	$ 0.75	$ 0.88	$ 0.73	$ 4.57	$ 3.21	$ 2.74
Pension settlement and related charges	$ 300,000	$ 800,000	$ 700,000	$ 1,100,000	$ 600,000	$ 2,100,000	$ 1,100,000	$ 400,000
Pension settlement and related charges (in dollars per share)	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.03	$ 0.01	$ 0.01
Amortization of Acquisition-related Intangible Assets			$ 600,000						$ 4,400,000	$ 3,400,000	$ 2,700,000
Tax benefit from stock-based compensation	$ 6,800,000	$ 2,000,000.0	$ 6,900,000	$ 5,100,000	$ 1,100,000	$ 4,000,000.0	$ 3,800,000	$ 1,400,000
Tax benefit from stock-based compensation (in dollars per share)	$ 0.09	$ 0.02	$ 0.09	$ 0.07	$ 0.02	$ 0.05	$ 0.05	$ 0.02
Intangible assets	$ 2,500,000		$ 1,600,000
Intangible assets (in dollars per share)	$ 0.03		$ 0.02
Restructuring and severance related charges		$ 3,400,000			$ 800,000	$ 1,400,000
Restructuring and severance related charges (in dollars per share)		$ 0.04			$ 0.02	$ 0.01
Devaluation of Argentina					$ 700,000	$ 700,000
Devaluation of Argentina diluted share (in dollars per share)					$ 0.01	$ 0.01
Tax benefit for impact of tax law changes enacted						$ 1,000,000.0			$ (500,000)	$ (300,000)	$ (2,500,000)
Tax benefit for impact of tax law changes enacted (in dollars per share)						$ 0.01
Fixed assets restructuring plan					$ 1,300,000
Fixed assets restructuring plan (in dollars per share)					$ 0.02
Payment of excise taxes					$ 2,900,000
Payment of excise taxes (in dollars per share)					$ 0.04
Daikyo
Restructuring Cost and Reserve [Line Items]
Amortization of Acquisition-related Intangible Assets				$ 1,000,000.0
Amortization expense (in dollars per share)				$ 0.01
Other acquisitions
Restructuring Cost and Reserve [Line Items]
Amortization of Acquisition-related Intangible Assets	$ 700,000	$ 700,000	$ 1,100,000
Amortization expense (in dollars per share)	$ 0.01	$ 0.01	$ 0.01