Unconsolidated Affiliates (Details 2) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Amounts and transactions with related party unconsolidated affiliates
DST's operating revenues from unconsolidated affiliates	$ 183.4	$ 192.0	$ 202.6
Unconsolidated affiliates
Amounts and transactions with related party unconsolidated affiliates
DST's operating revenues from unconsolidated affiliates	153.4	162.0	169.0
Amounts paid by DST to unconsolidated affiliates for products, services and leases	21.5	11.2	7.2
Amounts advanced (amounts received) by DST to (from) unconsolidated affiliates	(5.5)	(6.3)	(2.6)
Net proceeds received by DST from unconsolidated affiliates	6.4	16.1	3.8
Amounts receivable to DST from advances to unconsolidated affiliates	11.4	12.2
Trade accounts receivable to DST from unconsolidated affiliates	17.1	17.0
Amounts receivable to DST from unconsolidated affiliates	28.5	29.2
Amounts payable by DST to unconsolidated affiliates	2.2	5.3
Deferred revenue by DST from unconsolidated affiliates		40.0
Goodwill and intangible assets	4.8	7.2
Unconsolidated affiliates | Boston Financial Data Services, Inc.
Amounts and transactions with related party unconsolidated affiliates
Deferred revenue by DST from unconsolidated affiliates		40.0
Unconsolidated affiliates | Customer relationship assets | Boston Financial Data Services, Inc.
Amounts and transactions with related party unconsolidated affiliates
Intangible assets acquired in exchange for installment note		10.7
Amortization period (in years)		10
Installment period (in years)		5
Principal amount outstanding	7.9
Unconsolidated affiliates | Software license | Percana Limited
Amounts and transactions with related party unconsolidated affiliates
Intangible assets acquired		$ 2.0