Description of the business and recent developments: Basic and diluted net income per common share (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Diluted weighted average shares
Weighted-average common shares - basic (in shares)	45,754,880	45,354,327	45,760,302	45,349,397
Weighted average common shares-diluted	46,686,665	45,912,291	46,592,445	45,838,918
Stock options
Diluted weighted average shares
Dilutive effect (options or restricted stock)	205,823	35,895	128,477	30,972
Anti-dilutive effects
Anti-dilutive (options or restricted stock)	18,496	36,381	13,172	52,338
Restricted stock
Diluted weighted average shares
Dilutive effect (options or restricted stock)	725,962	522,069	703,666	458,549
Anti-dilutive effects
Unvested shares of restricted common stock	1,521,942	1,442,520	1,521,942	1,442,520
Anti-dilutive (options or restricted stock)		37,494		87,686