Description of Business and Basis of Presentation - Additional Information (Details)	9 Months Ended
	Sep. 30, 2019 USD ($) Segment	Jan. 01, 2019 USD ($)	Dec. 31, 2018 USD ($)
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Entity incorporation date	2008-09
Number of operating segment | Segment	1
Unbilled receivable, balance	$ 3,263,000		$ 6,032,000
Standard payment terms to customers minimum range	30 days
Standard payment terms to customers maximum range	90 days
Deferred costs amortization period	4 years
Operating lease right-of-use assets	$ 37,120,000
Operating lease liabilities	$ 47,896,000
ASU No 2016-02
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Operating lease right-of-use assets		$ 34,726,000
Operating lease liabilities		$ 46,205,000