Earnings Per Share - Components of Basic and Diluted Net Income Per Common Share (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Basic Net Income per Common Share Available to Common Stockholders:
Net income	$ 12,221,000	$ 10,137,000	$ 16,330,000	$ 20,136,000
Weighted average common shares outstanding	18,067,190	16,709,886	17,685,679	16,701,536
Basic earnings per common share	$ 0.68	$ 0.61	$ 0.92	$ 1.21
Diluted Net Income per Common Share Available to Common Stockholders:
Net income applicable to diluted earnings per share	$ 12,221,000	$ 10,137,000	$ 16,330,000	$ 20,136,000
Weighted average common shares outstanding	18,067,190	16,709,886	17,685,679	16,701,536
Dilutive potential common shares: restricted stock awarded	53,020	46,908	53,020	46,908
Diluted weighted average common shares outstanding	18,120,210	16,756,794	17,738,699	16,748,444
Diluted earnings per common share	$ 0.68	$ 0.60	$ 0.92	$ 1.20