Derivatives (Details Numeric) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended							3 Months Ended				6 Months Ended				3 Months Ended				6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 Business Solutions [Member]	Jun. 30, 2013 Business Solutions [Member]	Jun. 30, 2014 Business Solutions [Member]	Jun. 30, 2013 Business Solutions [Member]	Jun. 30, 2014 Consumer-to-Consumer [Member]	Jun. 30, 2013 Consumer-to-Consumer [Member]	Jun. 30, 2014 Consumer-to-Consumer [Member]	Jun. 30, 2013 Consumer-to-Consumer [Member]	Jun. 30, 2014 Interest Rate Contracts [Member]	Dec. 31, 2013 Interest Rate Contracts [Member]	Jun. 30, 2014 Interest Rate Contracts [Member] Notes Payable, 2015 [Member]	Jun. 30, 2014 Interest Rate Contracts [Member] Notes Payable, 2017 [Member]	Jun. 30, 2014 Interest Rate Contracts [Member] Notes Payable, 2018 [Member]	Jun. 30, 2014 Fair Value Hedges [Member]		Jun. 30, 2013 Fair Value Hedges [Member]		Jun. 30, 2014 Fair Value Hedges [Member]		Jun. 30, 2013 Fair Value Hedges [Member]		Jun. 30, 2014 Fair Value Hedges [Member] Fixed-rate debt [Member] Interest expense [Member]		Jun. 30, 2013 Fair Value Hedges [Member] Fixed-rate debt [Member] Interest expense [Member]		Jun. 30, 2014 Fair Value Hedges [Member] Fixed-rate debt [Member] Interest expense [Member]		Jun. 30, 2013 Fair Value Hedges [Member] Fixed-rate debt [Member] Interest expense [Member]		Jun. 30, 2014 Designated as hedges [Member] Foreign currency contracts [Member] Consumer-to-Consumer [Member]	Jun. 30, 2014 Designated as hedges [Member] Maximum [Member] Foreign currency contracts [Member] Consumer-to-Consumer [Member]	Jun. 30, 2014 Not designated as hedges [Member] Uncollected Settlement Assets and Obligations [Member] Consumer-to-Consumer [Member]	Jun. 30, 2014 Not designated as hedges [Member] Foreign currency denominated cash and other asset positions [Member] Consumer-to-Consumer [Member]	Jun. 30, 2014 Not designated as hedges [Member] Maximum [Member] Business Solutions [Member]
Derivative instruments [Line Items]
Derivative policy - contract maturity period maximum																																			36 months
Derivative policy - targeted weighted-average maturity																																		1 year
Maximum remaining maturity of foreign currency derivatives																																			24 months
Derivative weighted-average maturity																																		1 year				1 year
Foreign currency forward contracts maturity range minimum																																				2 days
Foreign currency forward contracts maturity range maximum																																				1 month	1 year
Foreign exchange revenues	$ 344.3	$ 338.0	$ 673.6	$ 650.4	$ 87.7	$ 88.7	$ 178.1	$ 172.7	$ 249.6	$ 246.0	$ 485.6	$ 471.6
Notional amounts					6,000.0		6,000.0						1,050.0	1,550.0	250.0	500.0	300.0
Gain/(Loss) recognized in income on related hedged item																		(4.2)	[1]	10.2	[1]	(4.5)	[1]	13.5	[1]	(4.2)	[1]	10.2	[1]	(4.5)	[1]	13.5	[1]
Gain/(loss) in value on the debt																										(6.9)		7.5		(10.5)		8.1
Amortization of hedge accounting adjustments																										2.7		2.7		6.0		5.4
Foreign exchange losses on settlement assets and obligations and cash balances	4.2	5.8	5.0	12.0
Accumulated other comprehensive pre-tax losses to be reclassified into revenue in next 12 months	12.1		12.1
Losses to be recognized on forecasted debt issuance hedges in next 12 months	$ 3.6		$ 3.6

[1] The gain/(loss) of $(4.2) million and $10.2 million in the three months ended June 30, 2014 and 2013, respectively, was comprised of a gain/(loss) in value on the debt of $(6.9) million and $7.5 million, respectively, and amortization of hedge accounting adjustments of $2.7 million for both periods. The gain/(loss) of $(4.5) million and $13.5 million in the six months ended June 30, 2014 and 2013, respectively, was comprised of a gain/(loss) in value on the debt of $(10.5) million and $8.1 million, respectively, and amortization of hedge accounting adjustments of $6.0 million and $5.4 million, respectively.