Debt - Additional Information (Detail)	12 Months Ended		12 Months Ended		12 Months Ended				1 Months Ended		1 Months Ended				12 Months Ended
	Jun. 30, 2013 USD ($)	Dec. 16, 2010 USD ($)	Jun. 30, 2013 Minimum USD ($)	Jun. 30, 2013 Maximum USD ($)	Jun. 30, 2013 Foreign Exchange Facility Wells Fargo	Jun. 30, 2013 Foreign Exchange Facility Bank of America, N.A.	Sep. 22, 2006 Natural Alternatives International Europe Sa USD ($)	Sep. 22, 2006 Natural Alternatives International Europe Sa CHF	Sep. 22, 2006 Natural Alternatives International Europe Sa Maximum	Sep. 22, 2006 Natural Alternatives International Europe Sa Current Account Loans	Sep. 22, 2006 Natural Alternatives International Europe Sa Fixed Loans USD ($)	Sep. 22, 2006 Natural Alternatives International Europe Sa Fixed Loans CHF	Feb. 19, 2007 Natural Alternatives International Europe Sa Amended Line of Credit Facility USD ($)	Feb. 19, 2007 Natural Alternatives International Europe Sa Amended Line of Credit Facility CHF	Jun. 30, 2013 London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 5,000,000					$ 1,400,000	1,300,000
Commitment fee	12,500
Net income after taxes to maintain credit agreement eligibility			750,000
Ratio of total liabilities to tangible net worth				1.25
Principal amount that bears fluctuating rate of interest				100,000
Variable interest rate															2.75%
Fixed interest rate															2.50%
Line of credit facility full payment period	Nov. 01, 2014
Outstanding balance to maintain under line of credit for period of at least 30 consecutive days	0
Period to maintain zero balance under line of credit			30 days
Prepayment amount of line of credit outstanding subject to fixed interest rate	100,000
Foreign exchange facility, expiration date					Nov. 01, 2014	Mar. 05, 2014
Annual reduction of maximum amount outstanding under the credit facility							169,000	160,000
Maximum aggregate amount that may be outstanding under credit facility after reduction													530,000	500,000
Line of credit facility, drawing term									24 months
Debt instrument, interest rate										5.00%
Pre-payment penalty rate											0.10%	0.10%
Minimum pre-payment penalty amount											1,058	1,000
Outstanding amount available under credit facilities	$ 5,500,000