Derivative Financial Instruments - Offsetting of Derivative Assets and Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Derivative Assets Subject to Master Netting Arrangement
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Assets	$ 46,666	$ 29,875
Gross Amounts Offset in the Consolidated Balance Sheet
Net Amounts of Assets Presented in the Consolidated Balance Sheet	46,666	29,875
Financial Instruments, Not Offset in the Consolidated Balance Sheet
Cash Collateral Received, Not Offset in the Consolidated Balance Sheet
Net Amount, Not Offset in the Consolidated Balance Sheet	46,666	29,875
Derivative Assets Not Subject to Master Netting Arrangement
Derivatives Fair Value [Line Items]
Gross Amounts Offset in the Consolidated Balance Sheet
Financial Instruments, Not Offset in the Consolidated Balance Sheet
Cash Collateral Received, Not Offset in the Consolidated Balance Sheet
Derivative Assets
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Assets	46,666	29,875
Gross Amounts Offset in the Consolidated Balance Sheet
Net Amounts of Assets Presented in the Consolidated Balance Sheet	46,666	29,875
Financial Instruments, Not Offset in the Consolidated Balance Sheet
Cash Collateral Received, Not Offset in the Consolidated Balance Sheet
Net Amount, Not Offset in the Consolidated Balance Sheet	46,666	29,875
Financial Assets
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Assets	46,666	29,875
Gross Amounts Offset in the Consolidated Balance Sheet
Net Amounts of Assets Presented in the Consolidated Balance Sheet	46,666	29,875
Financial Instruments, Not Offset in the Consolidated Balance Sheet
Cash Collateral Received, Not Offset in the Consolidated Balance Sheet
Net Amount, Not Offset in the Consolidated Balance Sheet	46,666	29,875
Derivative Liabilities Subject to Master Netting Arrangement
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Liabilities	75,182	67,036
Gross Amounts Offset in the Consolidated Balance Sheet	(48,186)	(27,020)
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	26,996	40,016
Financial Instruments, Not Offset in the Consolidated Balance Sheet
Cash Collateral Pledged, Not Offset in the Consolidated Balance Sheet
Net Amount, Not Offset in the Consolidated Balance Sheet	26,996	40,016
Derivative Liabilities Not Subject to Master Netting Arrangement
Derivatives Fair Value [Line Items]
Financial Instruments, Not Offset in the Consolidated Balance Sheet
Cash Collateral Pledged, Not Offset in the Consolidated Balance Sheet
Derivative Liabilities
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Liabilities	75,182	67,036
Gross Amounts Offset in the Consolidated Balance Sheet	(48,186)	(27,020)
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	26,996	40,016
Financial Instruments, Not Offset in the Consolidated Balance Sheet
Cash Collateral Pledged, Not Offset in the Consolidated Balance Sheet
Net Amount, Not Offset in the Consolidated Balance Sheet	26,996	40,016
Financial Liabilities
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Liabilities	75,182	67,036
Gross Amounts Offset in the Consolidated Balance Sheet	(48,186)	(27,020)
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	26,996	40,016
Financial Instruments, Not Offset in the Consolidated Balance Sheet
Cash Collateral Pledged, Not Offset in the Consolidated Balance Sheet
Net Amount, Not Offset in the Consolidated Balance Sheet	26,996	40,016
Santander And Affiliates | Interest Rate Swap
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Assets	3,067	1,601
Gross Amounts Offset in the Consolidated Balance Sheet
Net Amounts of Assets Presented in the Consolidated Balance Sheet	3,067	1,601
Financial Instruments, Not Offset in the Consolidated Balance Sheet
Cash Collateral Received, Not Offset in the Consolidated Balance Sheet
Net Amount, Not Offset in the Consolidated Balance Sheet	3,067	1,601
Gross Amounts of Recognized Liabilities	31,502	38,647
Gross Amounts Offset in the Consolidated Balance Sheet	(9,707)	(2,258)
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	21,795	36,389
Financial Instruments, Not Offset in the Consolidated Balance Sheet
Cash Collateral Pledged, Not Offset in the Consolidated Balance Sheet
Net Amount, Not Offset in the Consolidated Balance Sheet	21,795	36,389
Santander And Affiliates | Interest Rate Caps
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Assets	27,018	9,342
Gross Amounts Offset in the Consolidated Balance Sheet
Net Amounts of Assets Presented in the Consolidated Balance Sheet	27,018	9,342
Financial Instruments, Not Offset in the Consolidated Balance Sheet
Cash Collateral Received, Not Offset in the Consolidated Balance Sheet
Net Amount, Not Offset in the Consolidated Balance Sheet	27,018	9,342
Santander And Affiliates | Back To Back
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Liabilities	27,018	9,342
Gross Amounts Offset in the Consolidated Balance Sheet	(21,817)	(9,342)
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	5,201
Financial Instruments, Not Offset in the Consolidated Balance Sheet
Cash Collateral Pledged, Not Offset in the Consolidated Balance Sheet
Net Amount, Not Offset in the Consolidated Balance Sheet	5,201
Third Party | Interest Rate Caps
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Assets	16,581	18,932
Gross Amounts Offset in the Consolidated Balance Sheet
Net Amounts of Assets Presented in the Consolidated Balance Sheet	16,581	18,932
Financial Instruments, Not Offset in the Consolidated Balance Sheet
Cash Collateral Received, Not Offset in the Consolidated Balance Sheet
Net Amount, Not Offset in the Consolidated Balance Sheet	16,581	18,932
Third Party | Back To Back
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Liabilities	16,662	19,047
Gross Amounts Offset in the Consolidated Balance Sheet	(16,662)	(15,420)
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet		3,627
Financial Instruments, Not Offset in the Consolidated Balance Sheet
Cash Collateral Pledged, Not Offset in the Consolidated Balance Sheet
Net Amount, Not Offset in the Consolidated Balance Sheet		$ 3,627