Summary Of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2019 USD ($) segment	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Restricted cash	$ 15,000,000.0	$ 51,500,000
Other-than-temporary impairment losses	0	0	$ 0
Depreciation expense	$ 156,700,000	105,900,000	$ 82,100,000
Number of operating segments | segment	1
Performance obligation period	The Company’s system sale arrangements generally include a five-year period of service. The first year of service is generally free and included in the system sale arrangement, and the remaining four years are generally included at a stated service price.
System sales arrangement, warranty period	1 year
Capitalized contract costs	$ 51,500,000	$ 34,200,000
Market-based implied volatility (period)	1 year
Market-based implied volatility (percent)	100.00%
Cash flow hedges de-designated (period)	2 months
Likelihood of tax benefits being realized upon ultimate settlement	50.00%
Long-lived assets, percent	85.00%	88.00%
Minimum
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life, intangible asset	1 year
Sales-type leases term	24 months
Maximum
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life, intangible asset	9 years
Sales-type leases term	84 months
Derivative, term of contract	12 months
Maximum | Internal use software
Summary Of Significant Accounting Policies [Line Items]
Useful Lives	5 years
Accounts Receivable | U.S.
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	66.00%	71.00%
Total Revenue | U.S.
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	70.00%	71.00%	73.00%
Total Revenue | Outside of U.S. (“OUS”)
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	30.00%	29.00%	27.00%