Supplementary Balance Sheet Information - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Line Items]
Amortization expense related to conversion costs	$ 7,000,000	$ 4,500,000	$ 20,100,000	$ 12,900,000
Amortization related to payments for processing rights	$ 4,600,000	$ 4,400,000	12,400,000	$ 11,500,000
Reclassifications of AOCI			$ 0