Accounting for Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands				1 Months Ended	3 Months Ended		12 Months Ended
	Mar. 01, 2021	Mar. 01, 2020	Jul. 08, 2019	Jul. 31, 2020	May 31, 2021	May 31, 2020	Feb. 28, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock based compensation expense					$ 236	$ 351
Stock grants vested	100,000	100,000
Shares withheld for taxes	39,347
Patrick M. Lavelle [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Annual salary and cash bonus			$ 1,000
Stock based compensation expense					$ 61	$ 61
Grant of market stock units maximum amount			$ 5,000
Maximum average stock price of grant market stock units			$ 5.49
Maximum increase amount of market stock units award			$ 5,000
Maximum threshold share price increases in value of award			$ 15.00
Estimated Maximum threshold share increases in value of award			333,333
Patrick M. Lavelle [Member] | Common Class A [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value					$ 4.15	$ 4.15
Award vesting period			5 years
Grant of initial shares under employment agreement	60,653	100,000
Stock based compensation expense					$ 40	$ 103
Patrick M. Lavelle [Member] | Common Class A [Member] | March 1, 2021 [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Additional grant of shares under employment agreement			100,000
Patrick M. Lavelle [Member] | Common Class A [Member] | March 1, 2020 [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Additional grant of shares under employment agreement			100,000
Patrick M. Lavelle [Member] | Common Class A [Member] | March 1, 2022 [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Additional grant of shares under employment agreement			100,000
Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Allocated Share-based Compensation Expense					236	$ 351
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized					$ 1,233
2014 Plan [Member] | Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period							3 years
Share-based payment award vesting age of employee							65 years
Stock grants vested					100,000
2014 Plan [Member] | Restricted Stock Units [Member] | Employees [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted				48,269
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value				$ 5.76
2014 Plan [Member] | Restricted Stock Units [Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based payment award vesting required service period							10 years
2014 Plan [Member] | Unsettled Stock Grants and RSU Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock grants vested					278,318
Vested and unsettled awards, weighted average fair value					$ 7.71
2012 Equity Incentive Plan [Member] | Patrick M. Lavelle [Member] | Common Class A [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Grant of initial shares under employment agreement			200,000