Annual report pursuant to Section 13 and 15(d)

Line of Credit and Short-Term Borrowings - Additional Information (Detail)

v2.4.0.8
Line of Credit and Short-Term Borrowings - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
 1 Months Ended 12 Months Ended
Dec. 31, 2013
Dec. 31, 2013
Amendments
Jun. 30, 2009
Bank
Credit Facilities [Line Items]      
Amount of secured credit agreement     $ 250.0
Number of syndicate banks in agreement     6
Number of successive amendments to credit agreement   4  
Maturity date of amended credit agreement   Jun. 30, 2015  
Line of credit, subsidiaries   250.0  
Maximum amount of credit facility 300.0 300.0  
Line of credit facility, interest rate description   LIBOR  
Line of credit facility, interest rate   LIBOR plus 1.00%  
Line of credit facility, interest rate based on federal funds rate   0.50%  
Interest rate of line of credit agreement   1.00%  
Unused line of credit fee 0.25% 0.375%  
Maximum limit for letters of credit   50.0  
Maximum excess availability for credit agreement   40.0  
Syndication and commitment fees   $ 6.7  
Number of years for amortization of syndication and commitment fees   6 years  
Base Rate Loans [Member] | Minimum [Member]
      
Credit Facilities [Line Items]      
Interest rate of line of credit agreement   0.50%  
Base Rate Loans [Member] | Weighted Average [Member]
      
Credit Facilities [Line Items]      
Interest rate of line of credit agreement   0.75%  
Base Rate Loans [Member] | Maximum [Member]
      
Credit Facilities [Line Items]      
Interest rate of line of credit agreement   1.00%  
LIBOR Loans [Member] | Minimum [Member]
      
Credit Facilities [Line Items]      
Interest rate of line of credit agreement   1.50%  
LIBOR Loans [Member] | Weighted Average [Member]
      
Credit Facilities [Line Items]      
Interest rate of line of credit agreement   1.75%  
LIBOR Loans [Member] | Maximum [Member]
      
Credit Facilities [Line Items]      
Interest rate of line of credit agreement   2.00%