Long-term Debt and Capital Lease Obligations (Narrative) (Detail) (USD $)	12 Months Ended		12 Months Ended	1 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2010 Before Amendment [Member]	Jan. 31, 2011 After Amendment [Member]
Debt Instrument [Line Items]
Bank term loan	$ 12,600,000	$ 9,625,000	$ 9,625,000	$ 14,000,000
Bank term loan, maturity date			Mar. 31, 2013	Dec. 31, 2015
Bank term loan, quarterly repayment as a percent of the principal amount				2.50%
Bank term loan, repayment in the final quarter as a percent of the principal amount				8.75%
Bank term loan, interest rate over and above LIBOR, minimum	1.25%
Bank term loan, interest rate over and above LIBOR, maximum	2.25%
Bank term loan, effective interest rate	1.79%
Bank term loan, required minimum in unrestricted cash, cash equivalents and investments	$ 15,000,000
Capital leases, term in years	3 years
Capital leases, minimum effective interest rate	5.60%
Capital leases, maximum effective interest rate	7.20%