Annual report pursuant to Section 13 and 15(d)

Interest Rate Swap (Details)

Interest Rate Swap (Details) (USD $)
In Thousands, unless otherwise specified
1 Months Ended 12 Months Ended
May 31, 2011
Dec. 31, 2011
Interest Rate Swap [Abstract]    
Interest rate received in swap agreements 5.75%  
Interest rate paid on swap agreements LIBOR plus 3.5% LIBOR rate plus 3%
Fixed rate added to the LIBOR 3.50%  
Notional amount of interest rate swap agreements $ 250,000  
Variable interest rate   4.03%
Fair value of swap agreements   $ 11,431
Interest rate swap agreements expire date   June 1, 2017