Long Term Debt (Detail) (USD $)	Mar. 31, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Long-term debt including current portion	$ 78,800,000	$ 102,700,000
Current portion of long-term obligations	(35,807,000)	(35,807,000)
Total	43,000,000	66,900,000
Series A Notes [Member]
Debt Instrument [Line Items]
Long-term debt including current portion	0	20,000,000
Series B Notes [Member]
Debt Instrument [Line Items]
Long-term debt including current portion	20,000,000	20,000,000
Term Loan [Member]
Debt Instrument [Line Items]
Long-term debt including current portion	54,000,000	57,000,000
Promissory Notes
Debt Instrument [Line Items]
Long-term debt including current portion	$ 4,800,000	$ 5,700,000