Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands		Total		Common Stock [Member]		Additional Paid-In Capital [Member]		Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Deferred Compensation [Member]	Treasury Stock [Member]
Beginning Balances (shares) at Dec. 31, 2014	[1]			14,588,711
Beginning Balances at Dec. 31, 2014		$ 300,322	[2]	$ 7,100		$ 156,581		$ 142,317	$ (5,676)	$ 1,258	$ (1,258)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income		41,140						41,140
Other comprehensive loss		(164)							(164)
Dividend declared ($1.1325 per share)		(17,222)						(17,222)
Retirement savings plan and dividend reinvestment plan (shares)				43,275
Retirement savings plan and dividend reinvestment plan		2,235		$ 21		2,214
Common stock issued in acquisition (shares)				592,970
Common stock issued in acquisition		30,165		$ 289		29,876
Share-based compensation (shares)	[3],[4]			45,703
Share-based compensation and tax benefit		1,662	[4]	$ 22	[3]	1,640	[3]
Treasury stock activities		0								625	(625)
Ending Balances (shares) at Dec. 31, 2015	[1]			15,270,659
Ending Balances at Dec. 31, 2015		$ 358,138	[2]	$ 7,432		190,311		166,235	(5,840)	1,883	(1,883)
Preferred Stock, Shares Authorized		2,000,000
Preferred Stock, Par or Stated Value Per Share		$ 0.01
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income		$ 32,812						32,812
Other comprehensive loss		811							811
Dividend declared ($1.1325 per share)		(13,852)						(13,852)
Retirement savings plan and dividend reinvestment plan (shares)				30,041
Retirement savings plan and dividend reinvestment plan		$ 1,874		$ 15		1,859
Stock issuance, shares		960,488.00		960,488	[5]
Stock issuance		$ 57,306		$ 467	[5]	56,839
Share-based compensation (shares)	[3],[4]			36,099
Share-based compensation and tax benefit		1,211	[4]	$ 18	[3]	1,193	[3]
Treasury stock activities		0								593	(593)
Ending Balances (shares) at Sep. 30, 2016	[1]			16,297,287
Ending Balances at Sep. 30, 2016		$ 438,300	[2]	$ 7,932		$ 250,202		$ 185,195	$ (5,029)	$ 2,476	$ (2,476)
Preferred Stock, Shares Authorized		2,000,000
Preferred Stock, Par or Stated Value Per Share		$ 0.01

[1] Includes 80,024 and 70,631 shares at September 30, 2016 and December 31, 2015, respectively, held in a Rabbi Trust related to our Deferred Compensation Plan.

[2] 2,000 shares of preferred stock at $0.00001 par value has been authorized. None has been issued or is outstanding; accordingly, no information has been included in the statements of stockholders’ equity.

[3] Includes amounts for shares issued for Directors’ compensation.

[4] The shares issued under the SICP are net of shares withheld for employee taxes. For the nine months ended September 30, 2016, and for the year ended December 31, 2015, we withheld 12,031 and 12,620 shares, respectively, for taxes.

[5] On September 22, 2016, we completed a public offering of 960,488 shares of our common stock at a price per share of $62.26. The net proceeds from the sale of common stock, after deducting underwriting commissions and expenses, were approximately $57.3 million.