Acquisitions and Divestitures - Narrative (Details)	3 Months Ended
Mar. 31, 2018 businesses_acquired businesses_divested	Mar. 31, 2017 businesses_acquired businesses_divested
Business Combinations [Abstract]
Divestiture activity \| businesses_divested	0	0
Acquisition activity \| businesses_acquired	1	0

The number of businesses acquired by the entity during the period.

No definition available.

Name:	us-gaap_NumberOfBusinessesAcquired
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration