Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity - Shares (Details)

Stockholders' Equity - Shares (Details)	1 Months Ended		12 Months Ended
Stockholders' Equity - Shares (Details)	Aug. 31, 2014 shares	May. 31, 2014	Mar. 31, 2016 USD ($) item $ / shares shares	Mar. 31, 2015 USD ($) $ / shares shares	Mar. 31, 2014 USD ($) $ / shares shares	Jun. 30, 2000 shares
Shares
Nonvested, balance at the beginning of the period (in shares)			100,000	100,000
Nonvested, balance at the end of the period (in shares)			300,000	100,000	100,000
Additional disclosure
Share based compensation expenses \| $			$ 2,570,000	$ 2,236,000	$ 2,147,000
2000 Plan
Additional disclosure
Increase in common stock available under the plan	450,000
Number of shares of common stock reserved for issuance			1,849,000
Number of shares available for future grant			257,473
Purchase Plan
Additional disclosure
Number of shares of common stock reserved for issuance						70,000
Maximum amount that can be contributed by the employee \| $			$ 25,000
Maximum percentage of regular compensation that can be contributed by the employee			15.00%
Percentage of the fair market value of common stock on the last day of the purchase right period			95.00%
Options granted (in shares)			5,658	1,031	615
Number of shares available for future grant			14,820
Restricted stock units
Shares
Nonvested, balance at the end of the period (in shares)			2,343
Additional disclosure
Vesting period			4 years
Share based compensation expenses \| $			$ 891,000	$ 1,048,000	$ 914,000
Aggregate fair value of restricted stock units vested and issued \| $			$ 346,000	$ 1,206,000	$ 806,000
Weighted average grant date fair value of options granted during the period (in dollars per share) \| $ / shares			$ 3.34	$ 26.50	$ 21.90
Unrecognized compensation cost \| $			$ 1,000,000
Weighted average period for recognizing compensation cost			2 years 9 months 18 days
Options granted (in shares)				2,343
Restricted stock units \| Awards vesting over four years with one-fourth units vesting one year after the issuance date
Additional disclosure
Vesting period			1 year
Awards vesting percentage			25.00%
Restricted stock units \| Performance Restricted Stock Units
Shares
Nonvested, balance at the beginning of the period (in shares)			93,383
Granted (in shares)			234,046
Vested and issued (in shares)			(37,530)
Forfeited (in shares)			(33,112)
Nonvested, balance at the end of the period (in shares)			256,787	93,383
Awards expected to vest (in shares)			256,776
Weighted Average Grant-Date Fair Value
Nonvested restricted stock units outstanding at the beginning of the period (in dollars per share) \| $ / shares			$ 23.76
Granted (in dollars per share) \| $ / shares			3.86
Vested and issued (in dollars per share) \| $ / shares			24.28
Forfeited (in dollars per share) \| $ / shares			16.15
Nonvested restricted stock units outstanding at the end of the period (in dollars per share) \| $ / shares			6.53	$ 23.76
Awards expected to vest (in dollars per share) \| $ / shares			6.52
Non-employee director
Weighted Average Grant-Date Fair Value
Granted (in dollars per share) \| $ / shares			$ 1.41	$ 19.76	$ 25.26
Additional disclosure
Share based compensation expenses \| $			$ 431,000	$ 117,000	$ 116,000
Deferred stock awards granted			305,725	5,964	4,580
Non-employee director \| Restricted stock units
Additional disclosure
Vesting period			1 year
Chief Executive Officer \| PRSU Program
Shares
Granted (in shares)			10,000
Additional disclosure
Number of performance measurement periods to earn PRSU awards \| item			2
Share based compensation expenses \| $			$ 0
Weighted average grant date fair value of options granted during the period (in dollars per share) \| $ / shares			$ 15.50
Vesting right percentage of awards that will vest after end of applicable performance measurement period		50.00%
Vesting right percentage of awards that will vest one year after end of performance measurement period		50.00%