Joint Ventures and Other Equity Investments (Purchases of Compressors) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Equity Method Investments and Joint Ventures [Abstract]
Purchases of compressors from joint venture	$ 106.4	$ 97.7	$ 103.5

Purchases during the period (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

No definition available.

Name:	us-gaap_RelatedPartyTransactionPurchasesFromRelatedParty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration