Earnings Per Share (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Basic Net Income per Common Share Available to Common Stockholders [Abstract]
Net income	$ 4,654,000	$ 3,663,000	$ 4,156,000	$ 4,039,000	$ 3,910,000	$ 3,915,000	$ 4,029,000	$ 3,607,000	$ 16,512,000	$ 15,461,000	$ 14,722,000
Preferred stock dividends									(2,200,000)	(4,152,000)	(4,417,000)
Net income available to common stockholders	$ 4,104,000	$ 3,113,000	$ 3,606,000	$ 3,489,000	$ 3,071,000	$ 2,810,000	$ 2,925,000	$ 2,503,000	$ 14,312,000	$ 11,309,000	$ 10,305,000
Weighted average common shares outstanding									7,775,490	6,002,766	5,934,628
Basic earnings per common share	$ 0.49	$ 0.37	$ 0.50	$ 0.50	$ 0.48	$ 0.48	$ 0.49	$ 0.43	$ 1.84	$ 1.88	$ 1.74
Diluted Net Income per Common Share Available to Common Stockholders [Abstract]
Net income available to common stockholders	$ 4,104,000	$ 3,113,000	$ 3,606,000	$ 3,489,000	$ 3,071,000	$ 2,810,000	$ 2,925,000	$ 2,503,000	$ 14,312,000	$ 11,309,000	$ 10,305,000
Effect of assumed preferred stock conversion									2,200,000	4,152,000	0
Net income applicable to diluted earnings per share									$ 16,512,000	$ 15,461,000	$ 10,305,000
Weighted average common shares outstanding									7,775,490	6,002,766	5,934,628
Dilutive potential common shares [Abstract]
Assumed conversion of stock options									0	0	2,090
Restricted stock awarded									6,851	11,725	8,184
Assumed conversion of preferred stock									1,355,348	2,357,196	0
Dilutive potential common shares									1,362,199	2,368,921	10,274
Diluted weighted average common shares outstanding									9,137,689	8,371,687	5,944,902
Diluted earnings per common share	$ 0.48	$ 0.37	$ 0.49	$ 0.48	$ 0.47	$ 0.47	$ 0.48	$ 0.43	$ 1.81	$ 1.85	$ 1.73
Stock options to purchase shares of common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share (in shares)									45,500	52,000	130,500
Average dilutive potential common shares associated with convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share (in shares)									0	0	2,494,801