CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Stock [Member]	Retained Earnings (Deficit) [Member]	Total
Balance at Dec. 31, 2012	$ 39	$ 276,201	$ (306)	$ (62,970)	$ 21,449	$ 234,413
Balance (in shares) at Dec. 31, 2012	30,825,000
Proceeds from the exercise of stock options and sales of stock through the Employee Stock Purchase Plan	$ 0	332	0	0	0	332
Proceeds from the exercise of stock options and sales of stock through the Employee Stock Purchase Plan (in shares)	80,000
Net tax benefit from stock option exercises and restricted stock vesting	$ 0	2,578	0	0	0	2,578
Stock compensation related to restricted stock vesting and retirement savings plan contributions	$ 0	11,034	0	0	0	11,034
Stock compensation related to restricted stock vesting and retirement savings plan contributions (in shares)	949,000
Purchases of treasury stock and buyback of shares for taxes	$ 0	0	0	(18,081)	0	(18,081)
Purchases of treasury stock and buyback of shares for taxes (in shares)	(1,313,000)
Issuance of stock for acquisitions	$ 2	7,852	0	0	0	7,854
Issuance of stock for acquisitions (in shares)	800,000
Net income	$ 0	0	0	0	21,432	21,432
Foreign currency translation adjustment	0	0	(72)	0	0	(72)
Balance at Dec. 31, 2013	$ 41	297,997	(378)	(81,051)	42,881	259,490
Balance (in shares) at Dec. 31, 2013	31,341,000
Proceeds from the exercise of stock options and sales of stock through the Employee Stock Purchase Plan	$ 0	1,451	0	0	0	1,451
Proceeds from the exercise of stock options and sales of stock through the Employee Stock Purchase Plan (in shares)	210,000
Net tax benefit from stock option exercises and restricted stock vesting	$ 0	2,577	0	0	0	2,577
Stock compensation related to restricted stock vesting and retirement savings plan contributions	$ 1	12,718	0	0	0	12,719
Stock compensation related to restricted stock vesting and retirement savings plan contributions (in shares)	961,000
Purchases of treasury stock and buyback of shares for taxes	$ 0	0	0	(14,302)	0	(14,302)
Purchases of treasury stock and buyback of shares for taxes (in shares)	(807,000)
Issuance of stock for acquisitions	$ 1	19,902	0	0	0	19,903
Issuance of stock for acquisitions (in shares)	1,150,000
Net income	$ 0	0	0	0	23,163	23,163
Foreign currency translation adjustment	0	0	(273)	0	0	(273)
Balance at Dec. 31, 2014	$ 43	334,645	(651)	(95,353)	66,044	$ 304,728
Balance (in shares) at Dec. 31, 2014	32,855,000					32,854,802
Proceeds from the exercise of stock options and sales of stock through the Employee Stock Purchase Plan	$ 0	337	0	0	0	$ 337
Proceeds from the exercise of stock options and sales of stock through the Employee Stock Purchase Plan (in shares)	26,000
Net tax benefit from stock option exercises and restricted stock vesting	$ 0	1,335	0	0	0	1,335
Stock compensation related to restricted stock vesting and retirement savings plan contributions	$ 0	13,110	0	0	0	13,110
Stock compensation related to restricted stock vesting and retirement savings plan contributions (in shares)	893,000
Purchases of treasury stock and buyback of shares for taxes	$ 0	0	0	(7,844)	0	(7,844)
Purchases of treasury stock and buyback of shares for taxes (in shares)	(411,000)
Issuance of stock for acquisitions	$ 2	15,359	0	0	0	15,361
Issuance of stock for acquisitions (in shares)	1,031,000
Net income	$ 0	0	0	0	23,007	23,007
Foreign currency translation adjustment	0	0	(1,224)	0	0	(1,224)
Balance at Dec. 31, 2015	$ 45	$ 364,786	$ (1,875)	$ (103,197)	$ 89,051	$ 348,810
Balance (in shares) at Dec. 31, 2015	34,394,000					34,394,412