UNAUDITED CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Millions	Reliance Stockholders'	Common Stock and Additional Paid in Capital	Retained Earnings	Accumulated Other Comprehensive (Loss) Income	Non-controlling Interests	Total
Balance at Dec. 31, 2023		$ 0.1	$ 7,798.9	$ (76.7)	$ 10.5	$ 7,732.8
Increase (Decrease) in Stockholders' Equity
Net income attributable to Reliance			570.7			570.7
Cash dividends			(125.7)
Dividend equivalents paid on vested restricted stock units			(2.2)
Other comprehensive income (loss)				(24.8)		(24.8)
Comprehensive income					1.4	(1.4)
Acquisition					0.3
Dividends paid					(2.2)
Stock-based compensation		26.9
Taxes paid related to net share settlement of restricted stock units		(13.2)	(10.9)
Repurchase of common shares		(13.7)	(505.6)
Excise tax on repurchase of common shares			(0.8)
Balance at Jun. 30, 2024	$ 7,623.0	0.1	7,724.4	(101.5)	10.0	7,633.0
Balance at Mar. 31, 2024		0.1	8,025.6	(93.3)	10.3	7,942.7
Increase (Decrease) in Stockholders' Equity
Net income attributable to Reliance			267.8			267.8
Cash dividends			(62.5)
Dividend equivalents paid on vested restricted stock units			(0.1)
Other comprehensive income (loss)				(8.2)		(8.2)
Comprehensive income					0.5	(0.5)
Acquisition					0.3
Dividends paid					(1.1)
Stock-based compensation		13.9
Taxes paid related to net share settlement of restricted stock units		(0.2)
Repurchase of common shares		(13.7)	(505.6)
Excise tax on repurchase of common shares			(0.8)
Balance at Jun. 30, 2024	7,623.0	0.1	7,724.4	(101.5)	10.0	7,633.0
Balance at Dec. 31, 2024		0.1	7,334.7	(115.2)	11.0	7,230.6
Increase (Decrease) in Stockholders' Equity
Net income attributable to Reliance			433.4			433.4
Cash dividends			(126.8)
Dividend equivalents paid on vested restricted stock units			(1.5)
Other comprehensive income (loss)				29.0		29.0
Comprehensive income					1.3	(1.3)
Dividends paid					(2.3)
Stock-based compensation		28.1
Taxes paid related to net share settlement of restricted stock units			(11.6)
Repurchase of common shares		(28.1)	(305.0)
Excise tax on repurchase of common shares			(3.0)
Balance at Jun. 30, 2025	7,234.1	0.1	7,320.2	(86.2)	10.0	7,244.1
Balance at Mar. 31, 2025		0.1	7,214.5	(112.8)	11.8	7,113.6
Increase (Decrease) in Stockholders' Equity
Net income attributable to Reliance			233.7			233.7
Cash dividends			(63.1)
Other comprehensive income (loss)				26.6		26.6
Comprehensive income					0.5	(0.5)
Dividends paid					(2.3)
Stock-based compensation		15.9
Taxes paid related to net share settlement of restricted stock units			(0.1)
Repurchase of common shares		(15.9)	(64.0)
Excise tax on repurchase of common shares			(0.8)
Balance at Jun. 30, 2025	$ 7,234.1	$ 0.1	$ 7,320.2	$ (86.2)	$ 10.0	$ 7,244.1