Variable Interest Entities - Transfer of Payroll Loans (Details) - Payroll Loans [Member] - Grupo Finmart [Member] $ in Millions	Dec. 31, 2014 USD ($) loan	Sep. 30, 2014 USD ($) loan	Jun. 30, 2014 USD ($) loan	Mar. 31, 2014 USD ($) loan	Oct. 31, 2013 USD ($) loan
VIE C [Member]
Variable Interest Entity [Line Items]
Number of loans transferred | loan					14,500
Carrying (par) value of principal of loans transferred					$ 14.0
Carrying value of accrued interest of loans transferred					0.7
Principal of VIE promissory note issued at par					$ 19.3
VIE B [Member]
Variable Interest Entity [Line Items]
Number of loans transferred | loan	10,900	16,135	7,100	7,500
Carrying (par) value of principal of loans transferred	$ 13.9	$ 26.7	$ 10.0	$ 10.0
Carrying value of accrued interest of loans transferred	1.5	3.3	2.1	1.3
Principal of VIE promissory note issued at par	$ 22.0	$ 43.8	$ 16.5	$ 16.0
VIE A [Member]
Variable Interest Entity [Line Items]
Number of loans transferred | loan			8,500
Carrying (par) value of principal of loans transferred			$ 14.0
Carrying value of accrued interest of loans transferred			2.3
Principal of VIE promissory note issued at par			$ 21.8