Quarterly report pursuant to Section 13 or 15(d)

Loans Payable and Other Borrowings Details Textual (Details)

v3.2.0.727
Loans Payable and Other Borrowings Details Textual (Details)
 3 Months Ended 6 Months Ended
Jun. 30, 2015
USD ($)
Jun. 30, 2015
USD ($)
Jul. 31, 2015
USD ($)
Dec. 31, 2014
USD ($)
Jul. 31, 2012
USD ($)
Line of Credit Facility [Line Items]          
Proceeds from Long-term Lines of Credit $ 110,000,000        
Letters of credit outstanding 17,591,000 $ 17,591,000   $ 19,489,000  
Line of Credit Facility, Remaining Borrowing Capacity $ 482,400,000 $ 482,400,000      
Notes Payable, Other Payables [Member]          
Line of Credit Facility [Line Items]          
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum   0.00%      
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Maximum   6.00%      
Letter of Credit [Member] | Line of Credit [Member]          
Line of Credit Facility [Line Items]          
Line of Credit Facility, Maximum Borrowing Capacity       200,000,000  
Revolving Credit Facility [Member] | London Interbank Offered Rate (LIBOR) [Member]          
Line of Credit Facility [Line Items]          
Debt Instrument, Description of Variable Rate Basis   LIBOR      
Debt Instrument, Base Rate 0.19% 0.19%      
Debt Instrument, Basis Spread on Variable Rate   1.75%      
Revolving Credit Facility [Member] | Prime Rate [Member]          
Line of Credit Facility [Line Items]          
Debt Instrument, Description of Variable Rate Basis   Prime      
Debt Instrument, Base Rate 3.25% 3.25%      
Debt Instrument, Basis Spread on Variable Rate   0.75%      
Revolving Credit Facility [Member] | Line of Credit [Member]          
Line of Credit Facility [Line Items]          
Line of Credit Facility, Maximum Borrowing Capacity $ 500,000,000 $ 500,000,000   $ 400,000,000 $ 125,000,000
Minimum Tangible Net Worth $ 670,300,000 $ 670,300,000      
Leverage ratio (as a percentage) 0.6 0.6      
Interest Coverage Ratio   1.5      
Subsequent Event [Member] | Revolving Credit Facility [Member] | Line of Credit [Member]          
Line of Credit Facility [Line Items]          
Line of Credit Facility, Maximum Borrowing Capacity     $ 600,000,000    
Line of Credit Facility, Accordion Feature, Increase Limit     $ 100,000,000