Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Total	Common stock	Additional paid-in capital	Retained earnings	Accumulated other comprehensive income (loss)
Balance at beginning of period at Dec. 31, 2021		$ 5.8	$ 96.2	$ 2,970.9	$ (30.7)
Balance at end of period at Mar. 31, 2022		5.8	101.6	3,063.0	(28.4)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividends paid per share of common stock (in dollars per share)	$ 0.31
Balance at beginning of period at Dec. 31, 2021		5.8	96.2	2,970.9	(30.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock options exercised			5.8
Purchases of common stock			(49.3)
Stock-based compensation			3.0
Net earnings	$ 556.7			556.7
Cash dividends paid				(356.9)
Translation adjustment upon merger of foreign subsidiary				0.9
Other comprehensive income (loss)					(23.7)
Balance at end of period at Jun. 30, 2022	$ 3,178.7	5.8	55.7	3,171.6	(54.4)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividends paid per share of common stock (in dollars per share)	$ 0.62
Balance at beginning of period at Dec. 31, 2021		5.8	96.2	2,970.9	(30.7)
Balance at end of period at Dec. 31, 2022	$ 3,163.2	5.7	3.6	3,218.7	(64.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividends paid per share of common stock (in dollars per share)	$ 1.24
Balance at beginning of period at Mar. 31, 2022		5.8	101.6	3,063.0	(28.4)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock options exercised			1.9
Purchases of common stock			(49.3)
Stock-based compensation			1.5
Net earnings	$ 287.1			287.1
Cash dividends paid				(178.5)
Translation adjustment upon merger of foreign subsidiary				0.0
Other comprehensive income (loss)					(26.0)
Balance at end of period at Jun. 30, 2022	$ 3,178.7	5.8	55.7	3,171.6	(54.4)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividends paid per share of common stock (in dollars per share)	$ 0.31
Balance at beginning of period at Dec. 31, 2022	$ 3,163.2	5.7	3.6	3,218.7	(64.8)
Balance at end of period at Mar. 31, 2023		5.7	11.4	3,314.0	(60.5)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividends paid per share of common stock (in dollars per share)	$ 0.35
Balance at beginning of period at Dec. 31, 2022	$ 3,163.2	5.7	3.6	3,218.7	(64.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock options exercised			12.5
Purchases of common stock			0.0
Stock-based compensation			3.8
Net earnings	593.1			593.1
Cash dividends paid				(399.7)
Translation adjustment upon merger of foreign subsidiary				0.0
Other comprehensive income (loss)					7.9
Balance at end of period at Jun. 30, 2023	$ 3,380.8	5.7	19.9	3,412.1	(56.9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividends paid per share of common stock (in dollars per share)	$ 0.70
Balance at beginning of period at Mar. 31, 2023		5.7	11.4	3,314.0	(60.5)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock options exercised			6.6
Purchases of common stock			0.0
Stock-based compensation			1.9
Net earnings	$ 298.0			298.0
Cash dividends paid				(199.9)
Translation adjustment upon merger of foreign subsidiary				0.0
Other comprehensive income (loss)					3.6
Balance at end of period at Jun. 30, 2023	$ 3,380.8	$ 5.7	$ 19.9	$ 3,412.1	$ (56.9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividends paid per share of common stock (in dollars per share)	$ 0.35