Severance Costs (Detail) - USD ($) $ in Thousands			3 Months Ended		9 Months Ended
	May. 28, 2015	Dec. 03, 2013	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Chief Executive Officer [Member]
Restructuring Cost and Reserve [Line Items]
Severance costs		$ 915
Chief Financial Officer [Member]
Restructuring Cost and Reserve [Line Items]
Severance costs	$ 941				$ 710
Chief Financial Officer [Member] | Accrued Expenses [Member]
Restructuring Cost and Reserve [Line Items]
Severance costs					346
Severance [Member]
Restructuring Reserve [Roll Forward]
Balance at beginning of period			$ 699	$ 547	89	$ 1,142
Provision for additional expense			0	0	722	313
Payments and adjustments			(355)	(313)	(467)	(1,221)
Balance at end of period			$ 344	234	$ 344	234
Severance [Member] | Chief Executive Officer [Member]
Restructuring Cost and Reserve [Line Items]
Severance payments				$ 104		$ 301