Commitments and Contingencies - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2016 USD ($) $ / shares shares	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) site $ / shares shares	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($) shares	Aug. 21, 2007 shares
Conversion of Stock [Line Items]
Reserves to satisfy Federal regulatory requirements	$ 77,248,000		$ 77,248,000		$ 70,660,000
Number of sites leased under non-cancelable operating leases | site			42
Rent expense under operating leases	1,009,000	$ 984,000	$ 1,990,000	$ 1,943,000
Rent expense offset by rent income	61,000	$ 56,000	$ 120,000	$ 104,000
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.
Accrued estimated probable losses with respect to legal proceedings	$ 1,450,000		$ 1,450,000
Class B common stock of Visa Inc. | shares	22,822,325		22,822,325		22,775,173	15,814,662
Conversion ratio	1.648265		1.648265
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	$ 74.17		$ 74.17
Value of unredeemed Class A equivalent shares	$ 1,638,000		$ 1,638,000