Quarterly report pursuant to Section 13 or 15(d)

Debt Instruments (Details)

v2.4.0.8
Debt Instruments (Details) (USD $)
In Millions, unless otherwise specified
 1 Months Ended 9 Months Ended 9 Months Ended 1 Months Ended 9 Months Ended
Sep. 30, 2013
Credit facility
Jul. 31, 2013
Credit facility
Oct. 31, 2013
Credit facility
May 31, 2011
Credit facility
Oct. 31, 2013
Credit facility
Alternate base rate
Oct. 31, 2013
Credit facility
Alternate base rate
Minimum
Oct. 31, 2013
Credit facility
Alternate base rate
Maximum
Oct. 31, 2013
Credit facility
LIBOR
Oct. 31, 2013
Credit facility
LIBOR
Minimum
Oct. 31, 2013
Credit facility
LIBOR
Maximum
Sep. 30, 2013
Letters of credit
Oct. 31, 2013
Letters of credit
May 31, 2012
Letters of credit
Oct. 31, 2013
Letters of credit
Minimum
Oct. 31, 2013
Letters of credit
Maximum
Debt Instruments                              
Maximum borrowings available $ 60.0     $ 30.0             $ 15.0   $ 5.0    
Decrease in the interest rate on borrowings (as a percent) 0.75%                            
Variable interest rate base         alternate base rate     LIBOR              
Margin (as a percent)           1.00% 1.25%   2.00% 2.25%          
Outstanding balance of borrowings     0                        
Non-usage charge (as a percent)     0.375%                        
Reduction in annual charge on outstanding amount (as a percent)                     0.75%        
Annual charge on outstanding amount (as a percent)                           2.00% 2.25%
Minimum liquidity requirement     5.0                        
Amount borrowed   10.0                          
Outstanding amount                       4.3      
Available borrowing capacity     $ 55.7