Annual report pursuant to Section 13 and 15(d)

Debt - Additional Information (Detail)

v2.4.0.6
Debt - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
1 Months Ended 12 Months Ended 1 Months Ended 12 Months Ended 12 Months Ended 12 Months Ended 9 Months Ended 12 Months Ended 1 Months Ended 12 Months Ended 1 Months Ended 1 Months Ended
Feb. 28, 2011
Jun. 30, 2010
Feb. 28, 2010
Dec. 31, 2011
Dec. 31, 2009
Dec. 31, 2012
Sep. 30, 2011
Jun. 30, 2010
Minimum
Dec. 31, 2009
Minimum
Dec. 31, 2009
Scenario 1
Dec. 31, 2009
Scenario 1
Minimum
Dec. 31, 2009
Scenario 2
Dec. 31, 2009
Scenario 2
Minimum
Dec. 31, 2011
Federal Funds Rate
Dec. 31, 2009
Federal Funds Rate
Feb. 28, 2011
Federal Funds Rate
Jun. 30, 2010
Federal Funds Rate
Maximum
Sep. 30, 2012
LIBOR
Dec. 31, 2011
LIBOR
Feb. 28, 2011
LIBOR
Dec. 31, 2009
LIBOR
Sep. 30, 2012
LIBOR
Minimum
Dec. 31, 2011
LIBOR
Minimum
Feb. 28, 2011
LIBOR
Minimum
Sep. 30, 2012
LIBOR
Maximum
Dec. 31, 2011
LIBOR
Maximum
Feb. 28, 2011
LIBOR
Maximum
Jun. 30, 2010
LIBOR
Maximum
Jun. 30, 2010
Wells Fargo
Minimum
Dec. 31, 2011
Wells Fargo's prime rate
Dec. 31, 2011
Wells Fargo's prime rate
Minimum
Feb. 28, 2011
Wells Fargo's prime rate
Minimum
Dec. 31, 2011
Wells Fargo's prime rate
Maximum
Feb. 28, 2011
Wells Fargo's prime rate
Maximum
Feb. 28, 2010
Term Loan
Dec. 31, 2009
Term Loan
Dec. 31, 2011
Revolving Credit Facility
Feb. 28, 2011
Revolving Credit Facility
Dec. 31, 2010
Revolving Credit Facility
Dec. 31, 2009
Revolving Credit Facility
Nov. 30, 2010
Term Loan Facility Additional Delayed Draw
Jun. 30, 2010
Term Loan Facility Additional Delayed Draw
Dec. 31, 2011
Standby Letters of Credit
Line of Credit Facility [Line Items]                                                                                      
Line of credit facility                                                                       $ 35.0   $ 37.0 $ 10.0 $ 10.0   $ 30.0  
Interest rate descriptions In addition, the interest rates on the term loan and revolving line of credit were amended to provide for a rate that was dependent on our leverage ratio and ranged from a stated rate of 2.75% to 3.25% plus LIBOR or, at our option, a stated rate of 0.0% to 0.5% plus Wells Fargo's prime rate (or, if greater, the federal funds rate plus 0.5% or three month LIBOR plus 1.0%). After the June 2010 amendment, the term loan and revolving line of credit bore interest at a stated rate of 3.5% plus LIBOR, or a stated rate of 0.75% plus Wells Fargo's prime rate (or, if greater, the federal funds rate plus 0.5% or three month LIBOR plus 1.0%).   Revolving loans accrue interest at a per annum rate equal to, at the Company's option, either LIBOR or Wells Fargo's prime rate (or, if greater, the federal funds rate plus 0.50% or three month LIBOR plus 1.00%), in each case plus a margin ranging from 2.50% to 3.00%, in the case of LIBOR loans, and 0.00% to 0.25% in the case of prime rate loans, based upon the Company's senior leverage ratio. The term loan and revolving line of credit bore interest at rates of the greater of 7.5%, a stated rate of 5.0% plus LIBOR (or if greater, 2.5%) or a stated rate of 5.0% plus the bank's prime rate (or, if greater than 3.5%, the federal funds rate plus 0.5% or three month LIBOR plus 1.0%).                 The federal funds rate plus 0.50% The federal funds rate plus 0.50%     The terms of the amendment, the LIBOR rate margin ranges from 2.00% to 2.50%, based on our senior leverage ratio 2.50% to 3.00% plus LIBOR                     0.00% to 0.25% plus Wells Fargo's prime rate                          
Line of credit facility, interest rate                 7.50%                                                                    
Basis spread on interest rate                     2.50%   3.50% 0.50% 0.50% 0.50% 0.50%   1.00% 1.00% 1.00% 2.00% 2.50% 2.75% 2.50% 3.00% 3.25% 1.00%     0.00% 0.00% 0.25% 0.50%                  
Stated interest rate above LIBOR rate               3.50%   5.00%                                                                  
Stated interest rate above prime rate                       5.00%                                 0.75%                            
Additional borrowing under credit facility                                                                     10.0           30.0    
Payment of quarterly installment on term loan     1.8                                                                                
Percentage of principal amount paid quarterly             3.75%                                                                        
Revolving line of credit facility borrowed   7.6   50.3   10.0                                                                          
Sub limit for issuance of letters of credit                                                                                     10.0
Revolving line of credit facility, available borrowing capacity           140.0                                                             150.0            
Principal together with accrued and unpaid interest due and payable, date       Dec. 30, 2015                                                                              
Unamortized debt issuance costs       1.3   0.8                                                                          
Issuance of letters of credit outstanding, amount           $ 10.0