Summary of Significant Accounting Policies - Finite Lived Assets (Details)	12 Months Ended
	Dec. 31, 2018
Trade names
Finite lived intangible assets - useful lives [Abstract]
Estimated Useful Life	5 years
Minimum | Trade names
Finite lived intangible assets - useful lives [Abstract]
Estimated Useful Life	2 years
Minimum | Other
Finite lived intangible assets - useful lives [Abstract]
Estimated Useful Life	3 years
Maximum | Trade names
Finite lived intangible assets - useful lives [Abstract]
Estimated Useful Life	5 years
Maximum | Other
Finite lived intangible assets - useful lives [Abstract]
Estimated Useful Life	9 years