Description of the business and recent developments: Basic and diluted net income per common share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Diluted weighted average shares
Weighted-average common shares - basic (in shares)	45,815,718	45,438,656	45,818,677	45,428,305
Weighted average common shares-diluted	45,815,718	46,019,691	46,598,870	45,948,331
Stock options
Diluted weighted average shares
Dilutive effect (options or restricted stock)		34,593	99,581	32,179
Anti-dilutive effects
Anti-dilutive (options or restricted stock)	87,214	37,606	24,453	50,928
Restricted stock
Diluted weighted average shares
Dilutive effect (options or restricted stock)		546,442	680,612	487,847
Anti-dilutive effects
Unvested shares of restricted common stock	1,472,572	1,379,446	1,472,572	1,379,446
Anti-dilutive (options or restricted stock)	925,866		191	50,292