Selected Quarterly Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2016

Quarterly Financial Information Disclosure [Abstract]

Schedule of Quarterly Financial Information

							Net Income (Loss)
(In thousands, except per share amounts)	Revenues		Gross Profit		Operating Income		Amount		Per Basic Share		Per Diluted Share
Year Ended December 31, 2016:
4th Quarter	$	283,667	$	169,254	$	60,796	$	32,455	$	0.26	$	0.26
3rd Quarter	284,095		170,227		86,828		47,909		0.38		0.38
2nd Quarter	280,734		171,773		92,368		61,993		0.51		0.50
1st Quarter	268,347		163,017		87,579		41,886		0.35		0.34
Year Ended December 31, 2015:
4th Quarter	$	279,977	$	174,430	$	64,475	$	32,785	$	0.27	$	0.27
3rd Quarter	256,801		163,012		90,767		47,967		0.40		0.39
2nd Quarter	220,920		128,407		66,102		32,508		0.28		0.27
1st Quarter	227,378		130,163		73,267		37,538		0.33		0.31