EARNINGS PER COMMON SHARE - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Numerator for basic and diluted earnings per share -income available to common shareholders:
Net income	$ 50,657	$ 24,826	$ 117,581	$ 71,976
Denominator for basic earnings per share - weighted average shares	97,411,201	61,577,619	85,602,116	61,507,160
Effect of dilutive securities -
Employee stock awards	536,760	552,774	515,566	617,128
Warrants	536,267	59,244	522,245	61,586
Denominator for diluted earnings per share - adjusted weighted average shares	98,484,228	62,189,637	86,639,927	62,185,874
Basic	$ 0.52	$ 0.40	$ 1.37	$ 1.17
Diluted	$ 0.51	$ 0.40	$ 1.36	$ 1.16