Stockholders' Equity - Number and Cost of Employee Stock Plan Repurchases (Details) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Equity [Abstract]
Repurchases related to employee stock plans (in shares)	362	347	366
Repurchases related to employee stock plans	$ 37,678	$ 29,817	$ 17,399

Value of shares repurchased in connection with employee stock plans, whereby Company shares were tendered by employees for the payment of applicable withholding taxes and/or exercise price.

No definition available.

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Namespace Prefix:	rhi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration