Contingencies (Details) (Pending Litigation)	0 Months Ended	3 Months Ended	0 Months Ended
	Apr. 17, 2013 People	Mar. 31, 2015 Litigation_case	Apr. 17, 2015 Insurance_company Entity Plaintiff People
Loss Contingencies [Line Items]
Number of people killed	15
Number of people injured	200
Number of litigation cases scheduled for trial		3
Subsequent Event
Loss Contingencies [Line Items]
Number of plaintiffs			400
Number of entities that filed claims			9
Number of people that filed claims			325
Number of insurance companies that filed claims			80