Financial Instruments (Details) (USD $)
3 Months Ended
Mar. 31, 2014
Mar. 31, 2014
Interest Rate Swap [Member]
Mar. 31, 2014
Interest Rate Swap [Member]
Fair Value, Measurements, Recurring [Member]
Dec. 31, 2013
Fair Value, Inputs, Level 2 [Member]
Fair Value, Measurements, Recurring [Member]
Mar. 31, 2014
Fair Value, Inputs, Level 2 [Member]
Interest Rate Swap [Member]
Fair Value, Measurements, Recurring [Member]
Derivative [Line Items]          
Length of interest rate swap   3 years      
Notional amount of interest rate cash flow hedge derivatives   $ 500,000,000      
Libor rate   0.519%      
Effective interest rate   2.14%      
Basis spread on variable rate   1.625%      
Fair value of interest rate swap       1,719,000 1,858,000
Cash flow hedge loss reclassified to interest expense     400,000    
Deferred expenses related to derivative instruments $ 1,000,000