Legal settlements (Details) $ in Millions	12 Months Ended
Dec. 31, 2015 USD ($)
Legal Settlements [Abstract]
Legal settlement charge	$ 6.5
LegalSettlementChargeForLegalFees	0.7
Payments for Legal Settlements	7.5
Gross legal settlement award	8.8
Legal settlements	$ 5.3

The amount of cash paid for the settlement of litigation or for other legal issues during the period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3536-108585

Name:	us-gaap_PaymentsForLegalSettlements
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration