XML 112 R89.htm IDEA: XBRL DOCUMENT v3.5.0.2
Commitments and Contingencies (Details)
CAD in Millions, $ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2014
USD ($)
Dec. 31, 2013
USD ($)
Sep. 30, 2016
USD ($)
Sep. 30, 2016
CAD
Mar. 31, 2016
USD ($)
Loss Contingency, Damages Sought, Value | CAD       CAD 10.0  
Document Period End Date     Sep. 30, 2016 Sep. 30, 2016  
Walter Energy tax assessment     $ 33.0    
Amount receivable pending completion of an IRS audit     11.6    
Operating Leases          
Rent expense $ 10.4 $ 9.3 10.2    
Future minimum payment under non-cancelable operating leases, CY Plus 1     7.1    
Future minimum payment under non-cancelable operating leases, CY Plus 2     4.8    
Future minimum payment under non-cancelable operating leases, CY Plus 3     3.3    
Future minimum payment under non-cancelable operating leases, CY Plus 4     2.1    
Future minimum payment under non-cancelable operating leases, CY Plus 5     2.0    
Future minimum payment under non-cancelable operating leases, CY plus 6 and up     $ 5.1    
IRS-Walter Energy Claim 1 Total [Member]          
Loss Contingency, Range of Possible Loss, Maximum         $ 554.3
IRS-Walter Energy Claim 1 Priority [Member]          
Loss Contingency, Range of Possible Loss, Maximum         229.1
IRS-Walter Energy Claim 2 [Member]          
Loss Contingency, Range of Possible Loss, Maximum         860.4
IRS-Walter Energy Claim 2 Priority [Member]          
Loss Contingency, Range of Possible Loss, Maximum         $ 535.3