EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
EARNINGS PER SHARE
Net income	$ 35,491	$ 21,111	$ 13,763
Dividends paid on and earnings allocated to participating securities	(732)	(451)	(319)
Income attributable to common stock	$ 34,759	$ 20,660	$ 13,444
Weighted average common shares outstanding, including participating securities	17,670	14,792	11,633
Weighted average participating securities (in shares)	(366)	(319)	(278)
Weighted average common shares outstanding	17,304	14,473	11,355
Basic earnings per common share	$ 2.01	$ 1.43	$ 1.18
Income attributable to common stock	$ 34,759	$ 20,660	$ 13,444
Impact of assumed conversions - interest on 8.5% trust preferred securities	878
Income attributable to common stock including assumed conversions	$ 35,637	$ 20,660	$ 13,444
Weighted average common shares outstanding	17,304	14,473	11,355
Incremental shares from assumed conversions of options and restricted stock units	13	4
Incremental shares from assumed conversions of 8.5% trust preferred securities	534
Weighted average common and equivalent shares outstanding	17,851	14,477	11,355
Diluted earnings per common share (in dollars per share)	$ 2.00	$ 1.43	$ 1.18