Quarterly report pursuant to Section 13 or 15(d)

Line of Credit - Additional Information (Detail)

v2.4.0.8
Line of Credit - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
 9 Months Ended
Sep. 30, 2013
Sep. 12, 2013
Twelfth Amendment [Member]
Guarantor
Line of Credit Facility [Line Items]    
Revolving credit facility $ 80  
Revolving credit facility, maturity date Dec. 31, 2014  
Revolving credit facility, interest rate description Amounts borrowed under our revolving line of credit bear interest, at our option, at either the prime lending rate established by JPMorgan Chase Bank, N.A. or LIBOR plus 1.5 percent  
Revolving credit facility, interest rate above LIBOR 1.50%  
Revolving credit facility, unused annual commitment fee 0.25%  
Number of new guarantors   2
Revolving credit facility, amount outstanding 0  
Total outstanding letters of credit 48.7  
Revolving credit facility, unused portion 31.3  
Line of credit covenant, current ratio 1.25  
Line of credit covenant, debt to net worth 0.50  
Line of credit covenant, Earnings before interest, taxes, depreciation and amortization (EBITDA) to interest expense ratio 4.00  
Line of credit covenant, minimum net worth required $ 246.4