Accounts Receivable (Details) - USD ($)
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Allowance for doubtful accounts $ 21,000 $ 24,000  
Bad debt expense 0 1,424,000 $ 0
Selling, General and Administrative Expenses      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Bad debt expense $ 0 $ 1,400,000 $ 0