Commitments (Details) $ in Millions	Dec. 31, 2018 USD ($)
Capital Investment Commitments [Member]
Long-term Purchase Commitment [Line Items]
Commitments for future capital investments	$ 51.6

Minimum amount of purchase arrangement maturing in the next fiscal year following the latest fiscal year. Includes, but not limited to, recorded and unrecorded purchase obligations, long-term purchase commitments, and short-term purchase commitments.

No definition available.

Name:	us-gaap_PurchaseObligationDueInNextTwelveMonths
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant