Notes Payable and Credit Agreement (Details) - Line of Credit [Member]
Oct. 03, 2016
USD ($)
Apr. 18, 2014
USD ($)
credit_facility
Sep. 30, 2016
USD ($)
Jan. 04, 2016
USD ($)
Debt Instrument [Line Items]        
Number of credit facilities | credit_facility   2    
Maximum borrowing capacity       $ 125,000,000
Potential increase to maximum borrowing capacity       125,000,000
Debt issuance fees incurred       632,000
Debt issuance fees capitalized       448,000
Subsequent Event [Member]        
Debt Instrument [Line Items]        
Debt repayments $ 138,438,000      
Revolver [Member]        
Debt Instrument [Line Items]        
Maximum borrowing capacity   $ 225,000,000   275,000,000
Increase to maximum borrowing capacity       50,000,000
Revolver [Member] | Subsequent Event [Member]        
Debt Instrument [Line Items]        
Debt repayments 182,500,000      
Letter of Credit [Member]        
Debt Instrument [Line Items]        
Maximum borrowing capacity   40,000,000    
Revolving Credit Facility, Swing Line Loan [Member]        
Debt Instrument [Line Items]        
Maximum borrowing capacity   20,000,000    
Term Loan [Member]        
Debt Instrument [Line Items]        
Maximum borrowing capacity   $ 150,000,000   $ 75,000,000
Amortization rate as a percent of principal   5.00%    
Term Loan [Member] | Subsequent Event [Member]        
Debt Instrument [Line Items]        
Debt repayments 131,250,000      
Additional Term Loan [Member]        
Debt Instrument [Line Items]        
Scheduled annual payment     $ 3,750,000  
Additional Term Loan [Member] | Subsequent Event [Member]        
Debt Instrument [Line Items]        
Debt repayments $ 7,188,000