Marketable Securities and Derivative Instruments: Derivative Instrument (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Derivative [Line Items]
Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax	$ (233,218)	$ (27,195)	$ (220,525)	$ 40,844
JC Penney [Member]
Derivative [Line Items]
Investment Owned Balance Shares	23,400,000		23,400,000
Ownership Percentage	11.00%		11.00%
Closing share price	$ 23.31		$ 23.31
Economic Gain	(43,224)		(43,224)
Economic Cost Per Share	$ 26.41		$ 26.41
JC Penney [Member] | Derivative [Member]
Derivative Instrument That Does Not Qualify For Hedge Accounting [Abstract]
Derivative Number Of Instruments Held	4,815,990		4,815,990
Derivative Inception Date			Oct. 07, 2010
Derivative Maturity Date			Oct. 09, 2012
Derivative Price Risk Option Strike Price	$ 28.93		$ 28.93
Notional Amount Of Price Risk Derivatives	139,348		139,348
Derivative Basis Spread On Variable Rate	0.80%		0.80%
Derivative Gain On Derivative	(58,732)	(6,762)	(57,687)	10,401
JC Penney [Member] | Available-for-sale Securities [Member]
Derivative [Line Items]
Investment Owned Balance Shares	18,584,010		18,584,010
Acquisiton Price Per Share			$ 25.76
Investment Owned, at Cost	478,677		478,677
Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax	(225,383)	(25,611)	(220,180)	41,292
Investment Owned At Fair Value	$ 433,193		$ 433,193