XML 13 R23.htm IDEA: XBRL DOCUMENT  v2.3.0.11
Debt (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Jun. 30, 2011
Mar. 31, 2011
Debt    
Interest rate under the credit agreement The interest rate under the Credit Agreement is equal to LIBOR plus 1.75%  
Maximum unsecured borrowing capacity $ 50.0 $ 10.0
Minimum net worth 300.0  
Minimum cash flow leverage ratio 1.0  
Maximum cash flow leverage ratio 2.0  
Commitment fee charged on the unused line of credit 0.375%  
Outstanding letters of credit 2.6  
Unused and available borrowings under bank revolving line of credit $ 47.4