XML 44 R33.htm IDEA: XBRL DOCUMENT v3.7.0.1
Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)
 3 Months Ended 6 Months Ended
Dec. 31, 2015
Mar. 31, 2017
Sep. 30, 2016
Mar. 31, 2016
Sep. 30, 2015
Schedule Of Significant Accounting Policies [Line Items]          
Cash, cash equivalents, and restricted cash   $ 53,145,000 $ 139,188,000 $ 146,614,000 $ 100,508,000
Cash and cash equivalents   52,895,000 139,188,000    
Restricted cash   300,000      
Accrued expenses and other current liabilities   138,509,000 103,855,000    
Other long-term liabilities   25,728,000 25,255,000    
Deferred charges and other assets, net   9,946,000 11,074,000    
Long-term debt   $ 70,567,000 75,441,000    
Operating lease expiration year   2032      
Undiscounted future minimum lease payments through 2032   $ 118,900,000      
New England Teamsters & Trucking Industry Pension Fund          
Schedule Of Significant Accounting Policies [Line Items]          
Accrued expenses and other current liabilities   200,000      
Other long-term liabilities   17,400,000      
Significant Other Observable Inputs Level 2 | New England Teamsters & Trucking Industry Pension Fund          
Schedule Of Significant Accounting Policies [Line Items]          
Multiemployer plan discounted withdrawal liability   21,700,000      
Quoted Prices in Active Markets for Identical Assets Level 1          
Schedule Of Significant Accounting Policies [Line Items]          
Investments, debt securities   11,300,000      
Investments, mutual funds   300,000      
Accounting Standards Update 2015-03          
Schedule Of Significant Accounting Policies [Line Items]          
Deferred charges and other assets, net     11,100,000    
Long-term debt     75,400,000    
Accounting Standards Update 2015-03 | Scenario, Previously Reported          
Schedule Of Significant Accounting Policies [Line Items]          
Deferred charges and other assets, net     11,900,000    
Long-term debt     $ 76,300,000    
Subsidiaries of Swiss Re          
Schedule Of Significant Accounting Policies [Line Items]          
Weather hedge contracts, payment entitled to be received per heating degree-day shortfall   $ 35,000      
Percentage in heating degree days less than ten year average that is covered   92.50%      
Derivative maximum payout   $ 12,500,000      
Subsidiaries of Swiss Re | Delivery and branch expenses          
Schedule Of Significant Accounting Policies [Line Items]          
Credit on weather hedge contract $ 12,500,000 $ 0