Commitments - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Commitments [Line Items]
Rental expense	$ 2.5	$ 2.3
Vista, California
Commitments [Line Items]
Area of manufacturing facility leased	162,000
Operating lease expiry date	2014-03
Natural Alternatives International Europe Sa | Manno, Switzerland
Commitments [Line Items]
Area of manufacturing facility leased	59,239
Operating lease expiry date	2022-12
Operating lease effective date	Jan. 01, 2013