Equity and Cost Method Businesses - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Schedule Of Equity Method Investments [Line Items]
Carrying value of holdings in cost method companies	$ 18,100,000		$ 17,700,000
Impairment of equity method investment	0	0
Impairment of cost method investment	0	0
Acquirgy
Schedule Of Equity Method Investments [Line Items]
Loan repayment from Acquirgy, Inc.	400,000
Anthem
Schedule Of Equity Method Investments [Line Items]
Carrying value of holdings in cost method companies	0
Fair value of active common stock remaining	9.00%
Anthem | Other income (loss), net
Schedule Of Equity Method Investments [Line Items]
Proceeds from cost method investment	$ 1,000,000