Acquisitions - Preliminary Purchase Price Allocation of PAY.ON (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Goodwill	$ 917,470	$ 913,261
PAY.ON
Business Acquisition [Line Items]
Cash and cash equivalents	1,627
Receivables, net of allowance	2,674
Other current assets	513
Total current assets acquired	4,814
Property and equipment	424
Goodwill	140,783
Other noncurrent assets	7
Total assets acquired	204,259
Accounts payable	1,090
Employee compensation	676
Other current liabilities	1,073
Total current liabilities acquired	2,839
Deferred income taxes	15,047
Total liabilities acquired	17,886
Net assets acquired	$ 186,373
Software | PAY.ON
Business Acquisition [Line Items]
Acquired intangible assets, weighted-average useful lives	5 years
Amortizable intangible assets	$ 34,213
Customer relationships | PAY.ON
Business Acquisition [Line Items]
Acquired intangible assets, weighted-average useful lives	15 years
Amortizable intangible assets	$ 21,718
Trademarks | PAY.ON
Business Acquisition [Line Items]
Acquired intangible assets, weighted-average useful lives	5 years
Amortizable intangible assets	$ 2,300