QUARTERLY FINANCIAL INFORMATION (unaudited) (Tables)

12 Months Ended

Dec. 31, 2013

Quarterly Financial Information Disclosure [Abstract]

Summary of Selected Financial Information

The following table contains selected financial information from unaudited statements of income for each quarter of 2013 and 2012.

	Quarters Ended
	2013								2012
	Dec. 31		Sept. 30		June 30		Mar. 31		Dec. 31		Sept. 30		June 30		Mar. 31
Revenues	$	110,735	$	107,021	$	103,088	$	95,799	$	95,368	$	93,845	$	91,368	$	82,723
Gross profit		52,767		49,549		47,042		43,845		44,640		44,944		40,699		37,419
Income before income taxes		19,062		17,572		15,053		14,132		15,035		17,810		11,682		9,341
Net income		10,512		11,049		9,047		8,493		9,376		10,832		7,105		5,681
Earnings per diluted share		0.30		0.32		0.26		0.25		0.28		0.33		0.22		0.17
Shares used in computing diluted earnings per share		35,348		34,764		34,290		33,948		33,421		32,986		32,769		32,530