Acquisition of eSignLive - Schedule of Purchase Consideration Allocated to Assets and Liabilities Based on Estimated Acquisition-date Fair Values (Detail) - Silanis Technology Inc [Member] - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Cash	$ 610
Accounts receivable, net	3,856
Other current assets	4,215
Property and equipment	440
Current liabilities	(15,320)
Other non-current liabilities	(2,339)
Intangible assets	47,400
Goodwill	35,912
Net assets acquired	$ 74,774
As Previously Reported [Member]
Business Acquisition [Line Items]
Cash		$ 514
Accounts receivable, net		4,471
Other current assets		4,234
Property and equipment		416
Current liabilities		(16,896)
Other non-current liabilities		(8,070)
Intangible assets		30,000
Goodwill		60,331
Net assets acquired		75,000
Adjustment [Member]
Business Acquisition [Line Items]
Cash		96
Accounts receivable, net		(615)
Other current assets		(19)
Property and equipment		24
Current liabilities		1,576
Other non-current liabilities		5,731
Intangible assets		17,400
Goodwill		(24,419)
Net assets acquired		$ (226)