Summary of Significant Accounting Policies - Stock option equivalents (Details) - shares	Mar. 31, 2018	Mar. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total number of common stock equivalents outstanding (in shares)	430,000	361,000
Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total number of common stock equivalents outstanding (in shares)	151,000	139,000
Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total number of common stock equivalents outstanding (in shares)	193,000	133,000
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total number of common stock equivalents outstanding (in shares)	73,000	73,000
Option Matching Rights [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total number of common stock equivalents outstanding (in shares)	1,000	3,000
Restricted stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total number of common stock equivalents outstanding (in shares)	12,000	13,000