Commitments and Contingencies - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2016 USD ($) $ / shares shares	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) site $ / shares shares	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($) shares	Aug. 21, 2007 shares
Conversion of Stock [Line Items]
Reserves to satisfy Federal regulatory requirements	$ 78,813,000		$ 78,813,000		$ 70,660,000
Number of sites leased under non-cancelable operating leases | site			42
Rent expense under operating leases	1,034,000	$ 1,049,000	$ 3,024,000	$ 2,992,000
Rent expense offset by rent income	58,000	$ 57,000	$ 177,000	$ 161,000
Commitment expiration date			One year or less or other termination clauses and may require payment of a fee.
Letters of credit, issue period			One year or less
Overdraft privilege receivable criteria			All holders of such accounts who bring their accounts to a positive balance at least once every thirty days receive the overdraft privilege.
Cost of settlement	$ 1,450,000
Class B common stock of Visa Inc. | shares	22,827,277		22,827,277		22,775,173	15,814,662
Conversion ratio	1.648265		1.648265
Maximum [Member]
Conversion of Stock [Line Items]
Settlement amount	$ 1,900,000
Common Class B [Member]
Conversion of Stock [Line Items]
Class B common stock of Visa Inc. | shares	13,396		13,396
Common Class A [Member]
Conversion of Stock [Line Items]
The value of the Class A shares | $ / shares	$ 82.70		$ 82.70
Value of unredeemed Class A equivalent shares	$ 1,826,000		$ 1,826,000