Summary of Significant Accounting Policies and Basis of Presentation - Description of Business and Basis of Presentation (Details)	Dec. 31, 2017 country
Accounting Policies [Abstract]
Number of countries	30

The number of countries in which the entity operates as of balance sheet date.

No definition available.

Name:	us-gaap_NumberOfCountriesInWhichEntityOperates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant