Annual Fund Operating Expenses (dei_DocumentInformationDocumentAxis, (Oppenheimer Money Market Fund))	0 Months Ended
	Nov. 21, 2012
Class A
Operating Expenses:
Management Fees	0.41%
Distribution and/or Service (12b-1) Fees	none
Other Expenses	0.25%
Total Annual Fund Operating Expenses	0.66%
Fee Waiver and/or Expense Reimbursement	(0.35%)	[1]
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement	0.31%
Class Y
Operating Expenses:
Management Fees	0.41%
Distribution and/or Service (12b-1) Fees	none
Other Expenses	0.03%
Total Annual Fund Operating Expenses	0.44%
Fee Waiver and/or Expense Reimbursement	(0.14%)	[1]
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement	0.30%

[1] The Manager has voluntarily undertaken to waive fees and/or reimburse expenses to the extent necessary to assist the Fund in attempting to maintain a positive yield. There is no guarantee that the Fund will maintain a positive yield. The Manager is permitted to recapture previously waived and/or reimbursed fees in any given fiscal year if the recapture would not: (1) cause the Fund to generate a negative daily yield, and (2) exceed amounts previously waived and/or reimbursed under this arrangement during the current and prior three fiscal years. The reimbursement to the Manager of such previous waivers and reimbursements would not include any portion of distribution and/or service fees. This recapture could negatively affect each share class's future yield. This undertaking may not be amended or withdrawn until one year from the date of this prospectus.