Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Parenthetical) (Details) $ in Thousands	12 Months Ended
Dec. 31, 2018 USD ($)
Income Taxes [Abstract]
GILTI income deduction, related to Tax Act	$ 250

Tax cuts and jobs act of 2017, global intangible low taxed income, deduction.

No definition available.

Name:	rtec_TaxCutsAndJobsActOf2017GlobalIntangibleLowTaxedIncomeDeduction
Namespace Prefix:	rtec_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration