Components of Debt, Obligations, Weighted Average Interest Rate and Additional Fair Value Information Relating to Outstanding Debt Instruments (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012
Debt Instrument [Line Items]
Notes payable, carrying amount	$ 10,431	[1]	$ 12,003	[2]
Short-term debt, carrying amount	5,250		5,000
Total short-term debt, carrying amount	8,960	[1]	5,000	[2]
Long-term debt, carrying amount	34,750		17,167
Long-term debt, net of current portion	42,170	[1]	17,167	[2]
Notes payable, fair value	10,431		12,003
Short-term debt, fair value	5,250		4,892
Total short-term debt, fair value	8,960		4,892
Long term debt, non-current portion, fair value	34,750		16,336
Long term debt, fair value	42,170		16,336
Short-term Debt
Debt Instrument [Line Items]
Weighted Average Interest Rate	5.00%		2.20%
Total long-term debt
Debt Instrument [Line Items]
Weighted Average Interest Rate	4.91%		2.20%
Optical Components Business Units
Debt Instrument [Line Items]
Notes payable, carrying amount	3,710
Long-term notes payable, carrying amount	7,420
Notes payable, fair value	3,710
Long-term notes payable, fair value	$ 7,420
Optical Components Business Units | Short-term Debt | Notes Payable
Debt Instrument [Line Items]
Weighted Average Interest Rate	1.50%
Optical Components Business Units | Total long-term debt | Notes Payable
Debt Instrument [Line Items]
Weighted Average Interest Rate	1.50%

[1] Restated and Revised, see Notes 2 and 7

[2] Revised, see Note 2