EARNINGS PER COMMON SHARE (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net Income
Net income	$ 16,595,000	$ 11,116,000	$ 9,654,000	$ 12,073,000	$ 11,744,000	$ 11,696,000	$ 6,117,000	$ 8,766,000	$ 49,438,000	$ 38,323,000	$ 35,542,000
Diluted Earnings Per Common Share: Net income attributable to common shareholders and assumed conversions									$ 49,438,000	$ 38,323,000	$ 35,542,000
Weighted Average Shares
Basic Earnings Per Common Share: Average Shares									25,111,112	23,105,317	21,637,775
Diluted Earnings Per Common Share: Average Shares									25,514,638	23,431,355	21,909,370
Earnings per Common Share
Basic Earnings Per Common Share: Net income (in dollars per share)	$ 0.65	$ 0.43	$ 0.38	$ 0.50	$ 0.49	$ 0.49	$ 0.27	$ 0.41	$ 1.97	$ 1.66	$ 1.64
Diluted Earnings Per Common Share: Net income attributable to common shareholders and assumed conversions (in dollars per share)	$ 0.64	$ 0.43	$ 0.38	$ 0.49	$ 0.48	$ 0.48	$ 0.27	$ 0.40	$ 1.94	$ 1.64	$ 1.62
Stock warrants
Weighted Average Shares
Effect of dilutive warrants (in shares)									325,615	210,638	163,011
Stock options
Weighted Average Shares
Effect of dilutive stock options (in shares)									77,911	115,400	108,584
Earnings per Common Share
Antidilutive options											452