Fair Value Measurements (Details) (USD $)	3 Months Ended			6 Months Ended
	Jun. 30, 2011		Jun. 30, 2010	Jun. 30, 2011		Jun. 30, 2010	Dec. 31, 2010
Debt Instrument [Line Items]
Weighted Average Spread Over Libor	LIBOR plus 305 Libor plus 249 basis			LIBOR plus 305 Libor plus 249 basis
Derivatives
Subsidiary ILC cash and cash equivalents	$ 102,000,000			$ 102,000,000			$ 61,000,000
Subsidiary ILC short term investments	45,000,000			45,000,000			27,000,000
Subsidiary ILC long term investments	192,000,000			192,000,000			158,000,000
Subsidiary ILC total investments	339,000,000			339,000,000			246,000,000
Fair Value of Derivative Instruments [Abstract]
Fair Value Asset Derivatives Designated Foreign Exchange Contracts	41,000			41,000			160,000
Fair Value Asset Derivatives Designated Interest Rate Swaps	13,827,000			13,827,000			10,280,000
Fair Value Liability Derivatives Designated Foreign Exchange Contracts	980,000			980,000			716,000
Derivative Asset Not Designated As Hedging Instruments Fair Value	3,088,000			3,088,000			2,727,000
Derivative Liability Not Designated Foreign Exchange Contracts	2,032,000			2,032,000			6,191,000
Derivative Assets	16,956,000			16,956,000			13,167,000
Derivative Liabilities	3,012,000			3,012,000			6,907,000
Derivative Assets Liabilities At Fair Value Net	13,944,000			13,944,000			6,260,000
Derivatives In Fair Value Hedging Relationships [Abstract]
Derivative gain (loss) recognized in interest expense	4,961,000		4,089,000	12,179,000		8,619,000
Hedged item income (expense) recognized in interest expense	(10,109,000)		(8,125,000)	(20,219,000)		(16,250,000)
Derivatives In Cash Flow Hedging Relationships Currency [Abstract]
Total notional amount of outstanding contracts in cash flow hedging relationships	27,000,000			27,000,000			25,000,000
Derivative gain (loss) recognized in OCI for hedges recorded to revenue (effective portion)	618,000		1,092,000	303,000		1,137,000
Derivative gain (loss) recognized in OCI for hedges recorded to cost of sales (effective portion)	0		0
Derivative gain (loss) recognized in OCI for hedges (effective portion)	0		0
Derivative gain (loss) reclassified from AOCI to income for hedges recorded to revenue (effective portion)	(122,000)		305,000	(131,000)		467,000
Derivative gain (loss) reclassified from AOCI to income for hedges recorded to cost of sales (effective portion)	(292,000)		20,000	(554,000)		(158,000)
Derivative gain (loss) reclassified from AOCI to income for hedges (effective portion)	(414,000)		325,000	(685,000)		309,000
Derivatives Not Designated As Hedging Relationships [Abstract]
Derivative gain (loss) recognized in income	(13,619,000)		(336,000)	(20,861,000)		(7,471,000)
Amount of collateral that would be required to be posted if our long-term senior unsecured debt ratings was to have fallen below BB-/Ba3	1,000,000			1,000,000
General Fair Value Hedge Information [Abstract]
Weighted Average Spread Over Libor	LIBOR plus 305 Libor plus 249 basis			LIBOR plus 305 Libor plus 249 basis
Debt Due 2012 [Member]
Debt Instrument [Line Items]
Notional Amount Of Derivatives	400,000,000			400,000,000
Debt Instrument Face Amount	400,000,000			400,000,000
Debt Instrument Interest Rate Stated Percentage	462.50%			462.50%
General Fair Value Hedge Information [Abstract]
Notional Amount Of Derivatives	400,000,000			400,000,000
Debt Instrument Interest Rate Stated Percentage	462.50%			462.50%
Debt Due 2012 [Member] | One Month L I B O R 249 [Member]
Debt Instrument [Line Items]
Notional Amount Of Derivatives	850,000,000			850,000,000
General Fair Value Hedge Information [Abstract]
Notional Amount Of Derivatives	850,000,000			850,000,000
Debt Due 2014 [Member]
Debt Instrument [Line Items]
Notional Amount Of Derivatives	450,000,000			450,000,000
Debt Instrument Face Amount	450,000,000			450,000,000
Debt Instrument Interest Rate Stated Percentage	487.50%			487.50%
General Fair Value Hedge Information [Abstract]
Notional Amount Of Derivatives	450,000,000			450,000,000
Debt Instrument Interest Rate Stated Percentage	487.50%			487.50%
Fair Value, Inputs, Level 1 [Member]
Investment securities
Money market funds	371,439,000			371,439,000			256,074,000
Equity Securities	0			0			0
U.S. Government and agency issued debt	80,685,000			80,685,000			74,425,000
Corporate notes and bonds	0			0			0
Mortgage-backed securities	0			0			0
Derivatives
Interest rate swaps	0			0			0
Foreign exchange contracts	0			0			0
Total assets	452,124,000			452,124,000			330,499,000
Derivatives
Foreign exchange contracts	0			0			0
Total liabilities	0			0			0
Fair Value, Inputs, Level 2 [Member]
Investment securities
Money market funds	9,757,000			9,757,000			1,531,000
Equity Securities	24,486,000			24,486,000			23,410,000
U.S. Government and agency issued debt	31,580,000			31,580,000			30,725,000
Corporate notes and bonds	33,272,000			33,272,000			22,262,000
Mortgage-backed securities	120,825,000			120,825,000			106,479,000
Derivatives
Interest rate swaps	13,827,000			13,827,000			10,280,000
Foreign exchange contracts	3,129,000			3,129,000			2,887,000
Total assets	236,876,000			236,876,000			197,574,000
Derivatives
Foreign exchange contracts	3,012,000			3,012,000			6,907,000
Total liabilities	3,012,000			3,012,000			6,907,000
Fair Value, Inputs, Level 3 [Member]
Investment securities
Money market funds	0			0			0
Equity Securities	0			0			0
U.S. Government and agency issued debt	0			0			0
Corporate notes and bonds	0			0			0
Mortgage-backed securities	0			0			0
Derivatives
Interest rate swaps	0			0			0
Foreign exchange contracts	0			0			0
Total assets	0			0			0
Derivatives
Foreign exchange contracts	0			0			0
Total liabilities	0			0			0
Total Level [Member]
Investment securities
Money market funds	381,196,000			381,196,000			257,605,000
Equity Securities	24,486,000			24,486,000			23,410,000
U.S. Government and agency issued debt	112,265,000			112,265,000			105,150,000
Corporate notes and bonds	33,272,000			33,272,000			22,262,000
Mortgage-backed securities	120,825,000			120,825,000			106,479,000
Derivatives
Interest rate swaps	13,827,000			13,827,000			10,280,000
Foreign exchange contracts	3,129,000			3,129,000			2,887,000
Total assets	689,000,000			689,000,000			528,073,000
Derivatives
Foreign exchange contracts	3,012,000			3,012,000			6,907,000
Total liabilities	3,012,000			3,012,000			6,907,000
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value of Financial Instruments
Investment securities	668,170,000	[1]		668,170,000	[1]		512,771,000	[1]
Loans receivable	434,288,000	[1]		434,288,000	[1]		459,235,000	[1]
Derivatives, net	13,944,000	[1]		13,944,000	[1]		6,260,000	[1]
Long-term debt	(4,298,595,000)	[1]		(4,298,595,000)	[1]		(4,301,337,000)	[1]
Portion at Fair Value, Fair Value Disclosure [Member]
Fair Value of Financial Instruments
Investment securities	672,044,000			672,044,000			514,906,000
Loans receivable	434,288,000			434,288,000			459,235,000
Derivatives, net	13,944,000			13,944,000			6,260,000
Long-term debt	$ (4,507,309,000)			$ (4,507,309,000)			$ (4,388,923,000)

[1] Carrying value includes accrued interest and deferred fee income, where applicable.