Nature of Business and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Summary Of Significant Accounting Policies [Line Items]
Payments for partnership dissolved		$ 1,391
Percentage of receivables as of December 31, 2015, 2014	No customer accounted for more than 10% of the Company's consolidated receivables balance as of December 31, 2015 or 2014.
Amount of off balance sheet settlement funds	$ 260,200	224,900
Goodwill measurement period	1 year
Cornastone Technology Investments (Proprietary) Limited
Summary Of Significant Accounting Policies [Line Items]
Payments for partnership dissolved		$ 1,500
Minimum
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life	3 years
Minimum | Software Acquired or Developed for Internal Use
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life	3 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life	20 years
Maximum | Software Acquired or Developed for Internal Use
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life	10 years