Debt (Debt With A Contractual Term Greater Than One Year) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Gross long-term debt	$ 4,592,853,000	$ 4,807,706,000
Long-term Debt, Current Maturities	(1,176,140,000)	(437,162,000)
Long-term debt	3,416,713,000	4,370,544,000
Asset-Backed U.S. Commercial Paper Conduit Facility VIE [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Gross long-term debt	174,241,000	175,658,000
Term Asset-Backed Securitization VIEs [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Gross long-term debt	1,256,632,000	1,447,776,000
Long-term Debt, Current Maturities	(334,600,000)	(399,500,000)
Medium-Term Notes Due 2014 [Member]
Debt Instrument [Line Items]
Par value of debt instrument	500,000,000
Weighted average interest rate of asset-backed securitization transactions	5.75%
Medium-Term Notes Due 2014 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Gross long-term debt	499,866,000	499,705,000
Medium-Term Notes Due 2015 [Member]
Debt Instrument [Line Items]
Par value of debt instrument	600,000,000
Weighted average interest rate of asset-backed securitization transactions	1.15%
Medium-Term Notes Due 2015 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Gross long-term debt	599,543,000	599,269,000
Medium-Term Notes Due 2016 [Member]
Debt Instrument [Line Items]
Par value of debt instrument	450,000,000
Weighted average interest rate of asset-backed securitization transactions	3.88%
Medium-Term Notes Due 2016 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Gross long-term debt	449,883,000	449,829,000
Medium-Term Notes Due 2017 [Member]
Debt Instrument [Line Items]
Par value of debt instrument	400,000,000
Weighted average interest rate of asset-backed securitization transactions	2.70%
Medium-Term Notes Due 2017 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Gross long-term debt	399,946,000	399,929,000
Medium-Term Notes Due 2018 [Member]
Debt Instrument [Line Items]
Par value of debt instrument	910,500,000.0
Weighted average interest rate of asset-backed securitization transactions	6.80%
Medium-Term Notes Due 2018 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Gross long-term debt	909,742,000	932,540,000
Senior Notes Due 2014 [Member]
Debt Instrument [Line Items]
Par value of debt instrument	600,000,000
Weighted average interest rate of asset-backed securitization transactions	15.00%
Senior Notes Due 2014 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Gross long-term debt	$ 303,000,000	$ 303,000,000