Summary of Significant Accounting Policies - Additional Information (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) Customer shares	Dec. 31, 2018 USD ($) Customer shares	Dec. 31, 2017 USD ($) shares	Jan. 01, 2018 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Sales rebates	$ 6,200,000	$ 1,200,000	$ 200,000
Performance obligations remaining to be performed	$ 1,400,000,000	$ 1,100,000,000
Number of customers accounted for more than 10% of accounts receivable | Customer	0	0
Disbursement of pre-funded study costs			138,700,000
Fair value measurements transfers between level 1, level 2, or level 3	$ 0	$ 0	0
Accumulated deficit	68,109,000	(41,487,000)
Accounts receivable and unbilled, net	155,662,000	133,449,000
Deferred income tax liability	12,849,000	439,000
Accrued expenses	109,252,000	87,493,000
Pre-funded study costs		0
Advanced billings	$ 192,359,000	147,935,000
ASU 2014-09 | Impact of Adoption of ASC 606 - Adjustments
Summary Of Significant Accounting Policies [Line Items]
Accumulated deficit		2,637,000		$ 5,700,000
Accounts receivable and unbilled, net		(28,729,000)		23,900,000
Deferred income tax liability		2,049,000		(1,600,000)
Accrued expenses		(51,109,000)		35,100,000
Pre-funded study costs		61,156,000		(57,400,000)
Advanced billings		$ (41,732,000)		$ 38,900,000
Maximum
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of intangible assets	15 years
Maximum | Accounting Standard Update (“ASU”) No. 2016-09
Summary Of Significant Accounting Policies [Line Items]
Discrete Adjustments to Income Tax Expense Benefit			$ 100,000
Maximum | Computer Hardware Software Phone and Medical Imaging Equipment
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of assets	5 years
Maximum | Furniture and Fixtures and Other Equipment
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of assets	7 years
Maximum | Buildings
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of assets	40 years
Maximum | Computer Software Developed Costs
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of assets	3 years
Minimum
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of intangible assets	5 years
Minimum | Computer Hardware Software Phone and Medical Imaging Equipment
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of assets	3 years
Minimum | Furniture and Fixtures and Other Equipment
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of assets	5 years
Minimum | Buildings
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of assets	30 years
Stock Options
Summary Of Significant Accounting Policies [Line Items]
Anti-dilutive securities excluded from computation of diluted EPS | shares	248	121	63
Miscellaneous Income (Expense), Net
Summary Of Significant Accounting Policies [Line Items]
Net gain (loss) on foreign currency transactions	$ (600,000)	$ 400,000	$ (1,000,000.0)
Selling, General and Administrative
Summary Of Significant Accounting Policies [Line Items]
Advertisement expenses	$ 700,000	$ 800,000	$ 600,000