Commitments and Contingencies - Schedule of Material Contractual Obligations (Parenthetical) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2026	Dec. 31, 2025
Contractual obligations
Unrecognized tax benefit excluding foreign tax withholdings	$ 26,200
Unrecognized tax benefits	108,600	$ 108,000
Long-term deferred tax assets	$ 94,619	105,542
Software licenses
Contractual obligations
Terms of noncancellable license agreements, minimum (in years)	1 year
Location, Statement of Financial Position, Balance [Axis]: us-gaap:DeferredTaxAssetsGross
Contractual obligations
Unrecognized tax benefits	$ 25,100	24,300
Location, Statement of Financial Position, Balance [Axis]: us-gaap:TaxesPayableCurrentAndNoncurrent
Contractual obligations
Unrecognized tax benefits	800
Location, Statement of Financial Position, Balance [Axis]: rmbs:DeferredTaxAssetsLongTerm
Contractual obligations
Long-term deferred tax assets	25,100
Location, Statement of Financial Position, Balance [Axis]: rmbs:LongTermIncomeTaxesPayable
Contractual obligations
Unrecognized tax benefits		$ 1,000
Location, Statement of Financial Position, Balance [Axis]: rmbs:LongTermIncomeTaxesPayable \| Unrecognized tax benefits, including interest
Contractual obligations
Unrecognized tax benefits	$ 1,100