Commitments and Contingencies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Loss Contingencies [Line Items]
Net book value of assets held under capital leases	$ 0	$ 0
Accumulated amortization cost	510,000	510,000
Present value of the net minimum lease payments	0
Rental expense under operating leases	4,100,000	4,500,000	4,700,000
Purchase commitments	52,000,000
Estimate of potential settlements on legal and indemnification matters	14,300,000
Borrowings under the facility interest rate	1.00%
Cash equivalents and marketable securities held at bank	5,200,000
Company's unused borrowing capacity under credit facility	1,800,000
Amount borrowed against the facility	20,300,000	14,000,000
Outstanding borrowings under the credit facility	2,600,000
Cash [Member]
Loss Contingencies [Line Items]
Settlements on legal matters	6,000,000
Common Stock [Member]
Loss Contingencies [Line Items]
Settlements on legal matters	5,000,000
Secured Promissory Note [Member]
Loss Contingencies [Line Items]
Settlements on legal matters	$ 5,000,000
Secured note interest rate percentage	5.00%
Secured note maturity period	30 months
September Fifteenth Two Thousand Eight [Member]
Loss Contingencies [Line Items]
Lawsuit filing date	September 15, 2008
September Eighteenth Two Thousand Eight [Member]
Loss Contingencies [Line Items]
Lawsuit filing date	September 18, 2008