Significant Accounting Policies - Intangible Assets (Details)	12 Months Ended
	Dec. 31, 2019
Purchased software
Finite-Lived Intangible Assets [Line Items]
Useful life (in years)	3 years
Acquired technology \| Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life (in years)	2 years
Acquired technology \| Maximum
Finite-Lived Intangible Assets [Line Items]
Useful life (in years)	9 years
Customer relationships \| Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life (in years)	2 years
Customer relationships \| Maximum
Finite-Lived Intangible Assets [Line Items]
Useful life (in years)	5 years
Software development costs \| Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life (in years)	2 years
Software development costs \| Maximum
Finite-Lived Intangible Assets [Line Items]
Useful life (in years)	3 years
Other intangible assets \| Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life (in years)	3 years
Other intangible assets \| Maximum
Finite-Lived Intangible Assets [Line Items]
Useful life (in years)	10 years