Annual report pursuant to Section 13 and 15(d)

Commitments and Contingencies (Narrative) (Details)

v3.6.0.2
Commitments and Contingencies (Narrative) (Details)
$ in Millions
1 Months Ended 12 Months Ended
Feb. 10, 2017
USD ($)
Jan. 25, 2017
USD ($)
Jan. 24, 2017
USD ($)
Nov. 30, 2016
USD ($)
Jun. 30, 2016
USD ($)
Apr. 01, 2016
plaintiff
Mar. 08, 2013
Subcontractor
Feb. 28, 2017
USD ($)
Apr. 30, 2011
Employee
Dec. 31, 2016
Jun. 17, 2016
USD ($)
May 01, 2012
USD ($)
Loss Contingencies [Line Items]                        
Capitalization of construction costs                       $ 27.3
Number of subcontractors for lawsuits filed | Subcontractor             2          
Number of deaths of subcontractor employees | Employee                 5      
Operating Leases | Minimum                        
Loss Contingencies [Line Items]                        
Lease term                   2 years    
Operating Leases | Maximum                        
Loss Contingencies [Line Items]                        
Lease term                   15 years    
Building Facilities                        
Loss Contingencies [Line Items]                        
Lease term                   15 years    
Anchorage Litigation | Subsequent Event                        
Loss Contingencies [Line Items]                        
Settlement payments   $ 3.8                    
Anchorage Litigation | ICRC | Subsequent Event                        
Loss Contingencies [Line Items]                        
Settlement payments paid by insurers   $ 3.0                    
Heritage Disposal and Storage                        
Loss Contingencies [Line Items]                        
Settlement amount         $ 4.8              
Litigation settlement over estimated amount                     $ (1.5)  
Heritage Disposal and Storage | Subsequent Event                        
Loss Contingencies [Line Items]                        
Settlement amount     $ 3.5                  
Payments for legal settlements $ 3.3                      
Aviation Litigation                        
Loss Contingencies [Line Items]                        
Number of deaths | plaintiff           1            
Number of injured | plaintiff           2            
Damages sought       $ 1.0                
ICRC | Anchorage Litigation | Subsequent Event                        
Loss Contingencies [Line Items]                        
Proceeds from legal settlements               $ 10.4