Supplementary Balance Sheet Information - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Line Items]
Reclassifications of AOCI			$ 0
Conversion costs
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Line Items]
Amortization expense	$ 6,900,000	$ 7,000,000	21,300,000	$ 20,100,000
Payments for processing rights
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Line Items]
Amortization expense	$ 4,900,000	$ 4,600,000	$ 14,900,000	$ 12,400,000