Other Income, Net - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule of Other Nonoperating Income Expense [Line Items]
Gain from cost method investment	$ 2,800
Gain (loss) on sales/distributions of ownership interests	$ 2,959	$ 1,523	$ 5,158
Anthem
Schedule of Other Nonoperating Income Expense [Line Items]
Gain from cost method investment		1,000
Proceeds from sales / distributions of ownership interests		1,000
Acquirgy
Schedule of Other Nonoperating Income Expense [Line Items]
Loan repayment from equity / cost method investment		$ 400
Symbio
Schedule of Other Nonoperating Income Expense [Line Items]
Equity method investment, consideration as cash			8,100
Equity method investment, deferred gain on sale			800
Gain (loss) on sales/distributions of ownership interests			4,300
WhiteFence
Schedule of Other Nonoperating Income Expense [Line Items]
Gain on disposition of business			500
StarCite
Schedule of Other Nonoperating Income Expense [Line Items]
Proceeds from sales / distributions of ownership interests			$ 300