XML 21 R15.htm IDEA: XBRL DOCUMENT v2.3.0.15
Long-Term Debt (Narrative) (Details) (USD $)
3 Months Ended9 Months Ended
Sep. 30, 2011
Sep. 30, 2011
Dec. 31, 2010
Sep. 30, 2011
Tranche A Notes [Member]
Sep. 30, 2011
Tranche B Notes [Member]
Sep. 30, 2011
Letter Of Credit [Member]
Dec. 31, 2010
Letter Of Credit [Member]
Sep. 30, 2011
Sweep Program [Member]
Aug. 10, 2010
Five Year Senior Unsecured Revolving Credit Facility [Member]
Debt Instrument [Line Items]         
Notes issued$ 262,900,000$ 262,900,000       
Periodic principal payments 35,700,000       
Fixed interest rate, minimum 4.00%       
Fixed interest rate, maximum 5.85%       
Effective average interest rate5.13%5.13%5.54%      
Senior notes, noncurrent95,000,00095,000,000 50,000,00045,000,000    
Fixed interest rate   4.00%4.79%    
Maximum borrowing capacity300,000,000300,000,000   150,000,000 20,000,000 
Expired borrowing capacity225,000,000225,000,000       
Current borrowing capacity        200,000,000
Minimum increments under the additional borrowings 25,000,000       
Credit facility interest At our option, revolving loans under the facility bear interest at either: (a) the Applicable Margin Percentage for Base Rate Loans plus the higher of Wells Fargo's prime rate, the federal funds rate plus 0.5% per annum, or the one month LIBOR Rate plus 1.0% per annum; (b) the LIBOR Rate plus the Applicable Margin Percentage for LIBOR Loans; or (c) the LIBOR Market Index Rate ("LIBOR Index Rate") plus the Applicable Margin Percentage for LIBOR Market Index Loans       
Applicable margin interest on credit facility, low end 1.00%       
Applicable margin interest on credit facility, high end 1.875%       
Margin interest during period1.125%        
Decreases in marginal interest during period0.50%0.50%       
LIBOR rate1.00%1.00%       
Line of credit, outstanding$ 0$ 0$ 66,230,000  $ 50,800,000$ 49,600,000