Stockholders' Equity - Number and Cost of Employee Stock Plan Repurchases (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Equity [Abstract]
Employee stock plan repurchased (in shares)	191	239
Employee stock plan repurchased	$ 11,454	$ 9,876

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.

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