Business Acquisitions (Details) - USD ($) $ in Thousands					3 Months Ended	12 Months Ended
	Jul. 01, 2016	Jul. 31, 2015	Jun. 17, 2015	Jan. 23, 2015	Sep. 30, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Less:
Goodwill						$ 188,184	$ 56,342	$ 28,454
Pro forma information
Revenue						131,945	86,011
Net loss						$ (75,854)	$ (65,536)
HealthiestYou
Business acquisition
Purchase price	$ 151,500
Equity consideration (in shares)	6,955,796
Equity consideration	$ 108,300
Cash paid for acquisition	43,200
Transaction costs associated with acquisition	6,900
Contract termination costs associated with acquisition	5,700
Identifiable assets acquired and liabilities assumed:
Purchase price	151,484
Less:
Cash	6,204
Accounts receivable	1,184
Other assets	1,537
Accounts payable	(836)
Other liabilities	(2,847)
Goodwill	131,842
HealthiestYou | Maximum
Business acquisition
Adjustments for working capital	100
HealthiestYou | Client relationships
Less:
Finite-lived intangibles	10,930
HealthiestYou | Non-compete agreements
Less:
Finite-lived intangibles	70
HealthiestYou | Internal-Use Software
Less:
Finite-lived intangibles	2,220
HealthiestYou | Trademarks
Less:
Finite-lived intangibles	$ 1,180
Gateway to Provider Access, Inc.
Business acquisition
Purchase price		$ 1,500
Transaction costs associated with acquisition		100
Gateway to Provider Access, Inc. | Maximum
Business acquisition
Adjustments for working capital		$ 100
BetterHelp
Business acquisition
Purchase price				$ 3,300
Period of earn-out payments (in years)				4 years
Contingent future earn-out payments				$ 2,400
Issuance of unsecured subordinated promissory note				$ 1,000
Promissory note interest rate (as a percent)				5.00%
Identifiable assets acquired and liabilities assumed:
Purchase price				$ 5,749
Less:
Cash				89
Accounts receivable				11
Other assets				4
Accounts payable				(6)
Deferred tax				(666)
Other liabilities				(340)
Goodwill				4,686
BetterHelp | General and administrative expenses
Business acquisition
Transaction costs associated with acquisition				100
BetterHelp | Client relationships
Less:
Finite-lived intangibles				141
BetterHelp | Non-compete agreements
Less:
Finite-lived intangibles				910
BetterHelp | Internal-Use Software
Less:
Finite-lived intangibles				780
BetterHelp | Trademarks
Less:
Finite-lived intangibles				$ 140
StatDoc
Business acquisition
Purchase price			$ 30,100
Equity consideration (in shares)			1,051,033
Equity consideration			$ 16,800
Cash paid for acquisition			13,300
Identifiable assets acquired and liabilities assumed:
Purchase price			29,991
Less:
Cash			360
Accounts receivable			419
Other assets			70
Accounts payable			(609)
Other liabilities			(701)
Goodwill			23,202
StatDoc | Maximum
Business acquisition
Adjustments for working capital					$ 100
StatDoc | General and administrative expenses
Business acquisition
Transaction costs associated with acquisition					$ 300
StatDoc | Client relationships
Less:
Finite-lived intangibles			3,220
StatDoc | Non-compete agreements
Less:
Finite-lived intangibles			1,070
StatDoc | Internal-Use Software
Less:
Finite-lived intangibles			$ 2,960