Income per Share - Basis for Income per Share Computations (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2015	Sep. 28, 2014	Sep. 27, 2015	Sep. 28, 2014
Earnings Per Share [Abstract]
Income from continuing operations	$ 14,811	$ 33,847	$ 16,852	$ 59,018
Loss from discontinued operations, net of tax	(242)		(242)
Loss from disposal of discontinued operations, net of tax			(86)	(562)
Net income	$ 14,569	$ 33,847	$ 16,524	$ 58,456
Weighted average shares outstanding, basic	42,417	43,201	42,536	43,439
Effect of dilutive common stock equivalents	491	709	581	725
Weighted average shares outstanding, diluted	42,908	43,910	43,117	44,164