Restructuring Charges - Roll-Forward of Accrued Restructuring Expense (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2013
Restructuring Reserve Disclosures [Line Items]
Restructuring charge	$ 539	$ 534
Severance [Member]
Restructuring Reserve Disclosures [Line Items]
Accrued at January 1, 2013
Restructuring charge	437	437
Payments		(432)
Adjustment of restructuring charge		(5)
Accrued at December 31, 2013