Stock and employee benefit plans - Schedule of RSU Activity (Details) - Restricted Stock Units (RSUs)	3 Months Ended
	Mar. 31, 2020 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward]
Beginning Balance, Shares | shares	0
Granted (in shares) | shares	45,000
Vested, Shares | shares	0
Forfeited/cancelled, Shares | shares	0
Ending Balance, Shares | shares	45,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Beginning Balance, Weighted-Average Grant Date Fair Value | $ / shares	$ 0.00
Granted, Weighted-Average Grant Date Fair Value | $ / shares	1.98
Vested, Weighted-Average Grant Date Fair Value | $ / shares	0.00
Forfeited/cancelled, Weighted-Average Grant Date Fair Value | $ / shares	0.00
Ending Balance, Weighted-Average Grant Date Fair Value | $ / shares	$ 1.98