Quarterly report pursuant to Section 13 or 15(d)

Line of Credit - Additional Information (Detail)

v3.3.0.814
Line of Credit - Additional Information (Detail)
 9 Months Ended
Sep. 30, 2015
USD ($)
Line of Credit Facility [Line Items]  
Revolving credit facility $ 80,000,000
Revolving credit facility, extended maturity date Dec. 31, 2015
Revolving credit facility, interest rate description Amounts borrowed under the credit facility 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, amount outstanding $ 0
Total outstanding letters of credit 20,500,000
Revolving credit facility, unused portion $ 59,500,000
Revolving credit facility, interest rate above LIBOR 1.50%
Revolving credit facility, unused annual commitment fee 0.25%
Line of credit covenant, minimum net worth required $ 254,800,000.0
Line of credit covenant, debt to net worth 0.5
Line of credit covenant, Earnings before interest, taxes, depreciation and amortization (EBITDA) to interest expense ratio 4.0
Minimum  
Line of Credit Facility [Line Items]  
Line of credit covenant, current ratio 1.25