Basis of presentation (Tables)

12 Months Ended

Dec. 31, 2018

Accounting Policies [Abstract]

Summary of Basic and Diluted Earnings Per Common Share

The following is a summary of the basic and diluted earnings per common share calculation for each of the periods presented:

	December 31,
	2018			2017		2016
Basic earnings per common share calculation:
Net income	$	80,236		$	52,398	$	40,591
Dividends paid on and undistributed earnings allocated to participating securities	(428		)	—		—
Earnings attributable to common shareholders	$	79,808		$	52,398	$	40,591
Weighted-average basic shares outstanding	30,675,755			27,627,228		19,165,182
Basic earnings per common share	$	2.60		$	1.90	$	2.12
Diluted earnings per common share:
Earnings attributable to common shareholders	79,808			52,398		40,591
Weighted-average basic shares outstanding	30,675,755			27,627,228		19,165,182
Weighted-average diluted shares contingently issuable	639,226			580,374		146,992
Weighted-average diluted shares outstanding	31,314,981			28,207,602		19,312,174
Diluted earnings per common share	$	2.55		$	1.86	$	2.10
Pro forma earnings per common share:
Pro forma earnings attributable to common shareholders	$	79,808		$	52,398	$	39,422
Weighted-average basic shares outstanding	30,675,755			27,627,228.00		19,165,182.00
Pro forma basic earnings per common share	$	2.60		$	1.90	$	2.06
Pro forma diluted earnings per common share:
Pro forma earnings attributable to common shareholders	$	79,808		$	52,398	$	39,422
Weighted-average diluted shares outstanding	31,314,981			28,207,602		19,312,174
Pro forma diluted earnings per common share	$	2.55		$	1.86	$	2.04