2.2.0.25truefalse40201 - Disclosure - Acquisitions (Narrative) (Details)truefalsefalse1falsefalseUSDfalsefalse12/31/2010
USD ($)
USD ($) / shares
$As_Of_12_31_2010http://www.sec.gov/CIK0000093751instant2010-12-31T00:00:000001-01-01T00:00:00Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit1Standardhttp://www.xbrl.org/2003/instancesharesxbrli0Unit14Divide
http://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0Unit13Standardhttp://www.xbrl.org/2003/instancepurexbrli0USDUSD$2falsefalseUSDfalsefalse12/31/2009
USD ($)
USD ($) / shares
$As_Of_12_31_2009http://www.sec.gov/CIK0000093751instant2009-12-31T00:00:000001-01-01T00:00:00Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit1Standardhttp://www.xbrl.org/2003/instancesharesxbrli0Unit14Divide
http://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0Unit13Standardhttp://www.xbrl.org/2003/instancepurexbrli0USDUSD$3falsefalseUSDtruefalse{us-gaap_BusinessAcquisitionAxis} : Intesa Sanpaolo's Securities Services [Member]
12/31/2010
USD ($)
$As_Of_12_31_2010819http://www.sec.gov/CIK0000093751instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseIntesa Sanpaolo's Securities Services [Member]us-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldistt_IntesaSanpaolosSecuritiesServicesMemberus-gaap_BusinessAcquisitionAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso42
17USDiso42170USDUSD$4falsefalseUSDtruefalse{us-gaap_BusinessAcquisitionAxis} : Intesa Sanpaolo's Securities Services [Member]
6/30/2010
USD ($)
$As_Of_6_30_20103http://www.sec.gov/CIK0000093751instant2010-06-30T00:00:000001-01-01T00:00:00falsefalseIntesa Sanpaolo's Securities Services [Member]us-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldistt_IntesaSanpaolosSecuritiesServicesMemberus-gaap_BusinessAcquisitionAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217<
/MeasureSchema>USDiso42170USDUSD$5falsefalseUSDtruefalse{us-gaap_BusinessAcquisitionAxis} : Mourant International Finance Administration [Member]
6/30/2010
USD ($)
$As_Of_6_30_20102http://www.sec.gov/CIK0000093751instant2010-06-30T00:00:000001-01-01T00:00:00falsefalseMourant International Finance Administration [Member]us-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldistt_MourantInternationalFinanceAdministrationMemberus-gaap_BusinessAcquisitionAxisexplicitMemberUnit12Standardhttp://www.xbrl.or
g/2003/iso4217USDiso42170USDUSD$2false0stt_AssetsUnderCustodyAndAdministrationBusinessAcquiredMaysttfalsedebitinstantAssets Under Custody And Administration Business Acquired Mayfalsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsetruefalse4truefalsefalse564000000000564000000000falsetruefalsetruefalse5falsefalsefalse00falsefalsefalsetruefalseMonetaryxbrli:monetaryItemTypemonetaryAssets Under Custod
y And Administration Business Acquired MayNo authoritative reference available.falsefalse3false0us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillAmountus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3truefalsefalse932000000932000000falsefalsefalsetruefalse4falsefalsefalse00falsefalsefalsetruefalse5truefalsefalse7300000073000000falsefalsefalsetruefalseMonetaryxbrli:monetaryItemTypemonetaryAmount of goodwill arising from a business combination, which is the excess of the cost of the acquired entity over the amounts assigned to assets acquired and liabilities assumed.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 141
-Paragraph 52
-Subparagraph c
Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 141
-Paragraph 53
-Subparagraph d
falsefalse4false0us-gaap_IntangibleAssetsNetExcludingGoodwillus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse25930000002593000000falsefalsefalsefalsefalse2truefalsefalse18100000001810000000falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsetruefalse4falsefalsefalse00falsefalsefalsetruefalse5truefal
sefalse5900000059000000falsefalsefalsetruefalseMonetaryxbrli:monetaryItemTypemonetarySum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 142
-Paragraph 42, 45
falsefalse5false0stt_AssetsUnderCustodyAndAdministrationBusinessAcquiredsttfalsedebitinstantAssets Under Custody And Administration Business Acquiredfalsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsetruefalse4falsefalsefalse00falsefalsefalsetruefalse5true
falsefalse122000000000122000000000falsetruefalsetruefalseMonetaryxbrli:monetaryItemTypemonetaryAssets Under Custody And Administration Business AcquiredNo authoritative reference available.falsefalse54<
/NumberOfRows>Acquisitions (Narrative) (Details) (USD $)NoRoundingUnKnownUnKnownUnKnownfalsetrue
