Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_LossContingenciesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Environmental and legal matters Environmental and legal matters (Details)		9 Months Ended
	Mar. 20, 2014	Sep. 30, 2017
Loss Contingencies
Number of facilities served search and seizure warrants		3
Companies
Loss Contingencies
Number of Defendants	18
Individuals
Loss Contingencies
Number of Defendants	100
Subsidiaries
Loss Contingencies
Number of Defendants	2
Current employees
Loss Contingencies
Number of Defendants	2
Former employees
Loss Contingencies
Number of Defendants	1