CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($)		Stockholders' Equity, Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Other Comprehensive Income (Loss)	Treasury Stock
Equity Balance at Dec. 31, 2018		$ 531,977	$ 142	$ 30,121	$ 492,087	$ 9,627	$ 0
Net Income		55,720	0	0	55,720	0	0
Stock issued under Stock Option Plan		3,023	0	1,964	0	0	1,059
Common dividends declared	[1]	(24,524)	0	0	(24,524)	0	0
Other comprehensive gain		31,423	0	0	0	31,423	0
Reclassification of Treasury Stock per Maryland Law		0	0	0	210	0	(210)
Equity Balance at Sep. 30, 2019		596,770	142	32,085	523,493	41,050	0
Purchase of the Company's common stock		(849)	0	0	0	0	(849)
Equity Balance at Jun. 30, 2019		572,309	142	31,603	508,427	32,137	0
Net Income		19,732	0	0	19,732	0	0
Stock issued under Stock Option Plan		649	0	482	0	0	167
Common dividends declared	[2]	(4,833)	0	0	(4,833)	0	0
Other comprehensive gain		8,913	0	0	0	8,913	0
Reclassification of Treasury Stock per Maryland Law		0	0	0	167	0	(167)
Equity Balance at Sep. 30, 2019		596,770	142	32,085	523,493	41,050	0
Equity Balance at Dec. 31, 2019		603,066	143	33,510	537,167	32,246	0
Net Income		41,525	0	0	41,525	0	0
Stock issued under Stock Option Plan		1,162	0	1,029	0	0	133
Common dividends declared	[3]	(28,631)	0	0	(28,631)	0	0
Other comprehensive gain		23,388	0	0	0	23,388	0
Reclassification of Treasury Stock per Maryland Law		0	(4)	0	(15,730)	0	15,734
Equity Balance at Sep. 30, 2020		624,643	139	34,539	534,331	55,634	0
Purchase of the Company's common stock		(15,867)	0	0	0	0	(15,867)
Equity Balance at Jun. 30, 2020		626,728	141	34,230	533,346	59,011	0
Net Income		13,454	0	0	13,454	0	0
Stock issued under Stock Option Plan		346	0	309	0	0	37
Common dividends declared	[2]	(4,790)	0	0	(4,790)	0	0
Reclassification of Treasury Stock per Maryland Law		0	(2)	0	(7,679)	0	7,681
Equity Balance at Sep. 30, 2020		624,643	139	34,539	534,331	55,634	0
Other comprehensive loss		(3,377)	0	0	0	(3,377)	0
Purchase of the Company's common stock		$ (7,718)	$ 0	$ 0	$ 0	$ 0	$ (7,718)

[1] $1.39 per share

[2] $0.34 per share

[3] $2.02 per share