Basis of presentation (Tables)

6 Months Ended

Jun. 30, 2019

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:

	Three Months Ended June 30,						Six Months Ended June 30,
	2019			2018			2019			2018
Basic earnings per common share calculation:
Net income	$	18,688		$	22,065		$	38,276		$	41,819
Dividends paid on and undistributed earnings allocated to participating securities	(100		)	(117		)	(205		)	(223		)
Earnings attributable to common shareholders	$	18,588		$	21,948		$	38,071		$	41,596
Weighted-average basic shares outstanding	30,859,596			30,678,732			30,823,341			30,646,189
Basic earnings per common share	$	0.60		$	0.72		$	1.24		$	1.36
Diluted earnings per common share:
Earnings attributable to common shareholders	18,588			21,948			38,071			41,596
Weighted-average basic shares outstanding	30,859,596			30,678,732			30,823,341			30,646,189
Weighted-average diluted shares contingently issuable	518,422			615,312			525,625			629,657
Weighted-average diluted shares outstanding	31,378,018			31,294,044			31,348,966			31,275,846
Diluted earnings per common share	$	0.59		$	0.70		$	1.21		$	1.33