- Accounting Pronouncements Recently Adopted (Details) - USD ($)		3 Months Ended
	Jan. 01, 2018	Mar. 31, 2018	Apr. 01, 2017	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by financing activities		$ (4,934,000)	$ (546,000)
Net cash provided by operating activities		10,158,000	49,138,000
Best estimated selling price on upgrade rights		0.99
Revenue		247,865,000	298,942,000
Accounts receivable, net		214,355,000		$ 406,019,000
Deferred revenue		31,272,000		35,504,000
Accrued liabilities		382,384,000		452,137,000
Accumulated deficit		(214,116,000)		(132,112,000)
Accounting Standards Update 2014-09 [Member] | Accrued liabilities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reserves and accruals, returns and allowances		82,600,000
Accounting Standards Update 2014-09 [Member] | Accounts Receivable [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reserves and accruals, returns and allowances				$ 109,900,000
Accounting Standards Update 2016-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by operating activities			25,500
Deferred revenue		36,448,000
Minimum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated selling price		1.00
Maximum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated selling price		$ 3.00
Subscription-based Premium Services [Member] | Customer Concentration Risk [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Concentration risk, percentage		1.00%
Corporate Dashboard Tool [Member] | Customer Concentration Risk [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Concentration risk, percentage		1.00%
Advertising Barter Transactions [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Nonmonetary transaction, advertising credit utilized during the period		$ 100,000	$ 0
Under ASC 605 | Accounting Standards Update 2016-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	$ 247,051,000
Accounts receivable, net		131,743,000
Deferred revenue		37,514,000
Accrued liabilities		299,521,000
Accumulated deficit		(213,302,000)
Impact | Accounting Standards Update 2016-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	$ 814,000
Accounts receivable, net		82,612,000
Deferred revenue		(1,066,000)
Accrued liabilities		82,863,000
Accumulated deficit		$ (814,000)