Acquisitions - Preliminary Purchase Price Allocation of PAY.ON (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill	$ 913,261	$ 781,163	$ 669,217
PAY.ON
Business Acquisition [Line Items]
Cash and cash equivalents	1,627
Receivables, net of allowance	2,658
Other current assets	581
Total current assets acquired	4,866
Property and equipment	424
Goodwill	140,015
Other noncurrent assets	6
Total assets acquired	204,442
Accounts payable	1,125
Employee compensation	555
Other current liabilities	1,115
Total current liabilities acquired	2,795
Deferred income taxes	15,274
Total liabilities acquired	18,069
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	$ 22,418
Trademarks | PAY.ON
Business Acquisition [Line Items]
Acquired intangible assets, weighted-average useful lives	5 years
Amortizable intangible assets	$ 2,500