Summary of Significant Accounting Policies - Property and Equipment (Details)	6 Months Ended
Jun. 30, 2018
Minimum
Property, Plant and Equipment [Abstract]
Property and equipment, useful life	2 years
Maximum
Property, Plant and Equipment [Abstract]
Property and equipment, useful life	39 years

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

No definition available.

Name:	us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration