Derivative Financial Instruments - Offsetting of Derivative Assets and Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Derivative Assets Subject to Master Netting Arrangement
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Assets	$ 47,168	$ 29,875
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Net Amounts of Assets Presented in the Consolidated Balance Sheet	47,168	29,875
Financial Instruments, Not Offset in the Consolidated Balance Sheet	0	0
Cash Collateral Received, Not Offset in the Consolidated Balance Sheet	0	0
Net Amount, Not Offset in the Consolidated Balance Sheet	47,168	29,875
Derivative Assets Not Subject to Master Netting Arrangement
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Assets	0	0
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Net Amounts of Assets Presented in the Consolidated Balance Sheet	0	0
Financial Instruments, Not Offset in the Consolidated Balance Sheet	0	0
Cash Collateral Received, Not Offset in the Consolidated Balance Sheet	0	0
Net Amount, Not Offset in the Consolidated Balance Sheet	0	0
Derivative Assets
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Assets	47,168	29,875
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Net Amounts of Assets Presented in the Consolidated Balance Sheet	47,168	29,875
Financial Instruments, Not Offset in the Consolidated Balance Sheet	0	0
Cash Collateral Received, Not Offset in the Consolidated Balance Sheet	0	0
Net Amount, Not Offset in the Consolidated Balance Sheet	47,168	29,875
Financial Assets
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Assets	47,168	29,875
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Net Amounts of Assets Presented in the Consolidated Balance Sheet	47,168	29,875
Financial Instruments, Not Offset in the Consolidated Balance Sheet	0	0
Cash Collateral Received, Not Offset in the Consolidated Balance Sheet	0	0
Net Amount, Not Offset in the Consolidated Balance Sheet	47,168	29,875
Derivative Liabilities Subject to Master Netting Arrangement
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Liabilities	77,846	67,036
Gross Amounts Offset in the Consolidated Balance Sheet	(55,457)	(27,020)
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	22,389	40,016
Financial Instruments, Not Offset in the Consolidated Balance Sheet	0	0
Cash Collateral Pledged, Not Offset in the Consolidated Balance Sheet	0	0
Net Amount, Not Offset in the Consolidated Balance Sheet	22,389	40,016
Derivative Liabilities Not Subject to Master Netting Arrangement
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Liabilities	0	0
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	0	0
Financial Instruments, Not Offset in the Consolidated Balance Sheet	0	0
Cash Collateral Pledged, Not Offset in the Consolidated Balance Sheet	0	0
Net Amount, Not Offset in the Consolidated Balance Sheet	0	0
Derivative Liabilities
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Liabilities	77,846	67,036
Gross Amounts Offset in the Consolidated Balance Sheet	(55,457)	(27,020)
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	22,389	40,016
Financial Instruments, Not Offset in the Consolidated Balance Sheet	0	0
Cash Collateral Pledged, Not Offset in the Consolidated Balance Sheet	0	0
Net Amount, Not Offset in the Consolidated Balance Sheet	22,389	40,016
Financial Liabilities
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Liabilities	77,846	67,036
Gross Amounts Offset in the Consolidated Balance Sheet	(55,457)	(27,020)
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	22,389	40,016
Financial Instruments, Not Offset in the Consolidated Balance Sheet	0	0
Cash Collateral Pledged, Not Offset in the Consolidated Balance Sheet	0	0
Net Amount, Not Offset in the Consolidated Balance Sheet	22,389	40,016
Santander & Affiliates | Interest Rate Swaps
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Assets	537	1,601
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Net Amounts of Assets Presented in the Consolidated Balance Sheet	537	1,601
Financial Instruments, Not Offset in the Consolidated Balance Sheet	0	0
Cash Collateral Received, Not Offset in the Consolidated Balance Sheet	0	0
Net Amount, Not Offset in the Consolidated Balance Sheet	537	1,601
Gross Amounts of Recognized Liabilities	31,169	38,647
Gross Amounts Offset in the Consolidated Balance Sheet	(9,612)	(2,258)
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	21,557	36,389
Financial Instruments, Not Offset in the Consolidated Balance Sheet	0	0
Cash Collateral Pledged, Not Offset in the Consolidated Balance Sheet	0	0
Net Amount, Not Offset in the Consolidated Balance Sheet	21,557	36,389
Santander & Affiliates | Interest Rate Caps
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Assets	33,201	9,342
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Net Amounts of Assets Presented in the Consolidated Balance Sheet	33,201	9,342
Financial Instruments, Not Offset in the Consolidated Balance Sheet	0	0
Cash Collateral Received, Not Offset in the Consolidated Balance Sheet	0	0
Net Amount, Not Offset in the Consolidated Balance Sheet	33,201	9,342
Santander & Affiliates | Back to Back
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Liabilities	33,201	9,342
Gross Amounts Offset in the Consolidated Balance Sheet	(32,369)	(9,342)
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	832	0
Financial Instruments, Not Offset in the Consolidated Balance Sheet	0	0
Cash Collateral Pledged, Not Offset in the Consolidated Balance Sheet	0	0
Net Amount, Not Offset in the Consolidated Balance Sheet	832	0
Third Party | Interest Rate Caps
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Assets	13,430	18,932
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Net Amounts of Assets Presented in the Consolidated Balance Sheet	13,430	18,932
Financial Instruments, Not Offset in the Consolidated Balance Sheet	0	0
Cash Collateral Received, Not Offset in the Consolidated Balance Sheet	0	0
Net Amount, Not Offset in the Consolidated Balance Sheet	13,430	18,932
Third Party | Back to Back
Derivatives Fair Value [Line Items]
Gross Amounts of Recognized Liabilities	13,476	19,047
Gross Amounts Offset in the Consolidated Balance Sheet	(13,476)	(15,420)
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	0	3,627
Financial Instruments, Not Offset in the Consolidated Balance Sheet	0	0
Cash Collateral Pledged, Not Offset in the Consolidated Balance Sheet	0	0
Net Amount, Not Offset in the Consolidated Balance Sheet	$ 0	$ 3,627