Note 3. Investment Partnerships (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Sep. 24, 2014
Fair Value
Fair value of Partnership interest, beginning	$ 620,811	$ 734,668	$ 776,899	$ 455,297
Investment partnership gains (losses)	156,088	248,935	(110,956)	1,436
Investments (net of distributions)	0	(10,896)	68,725	164,078
Increase in proportionate share of Company stock held	0	0	0	0
Partnership interest, ending	776,899	972,707	734,668	620,811
Company Common Stock
Fair value of Partnership interest, beginning	63,573	262,979	78,917	57,598
Investment partnership gains (losses)	11,386	113,049	(71,600)	(12,619)
Investments (net of distributions)	0	0	0	0
Increase in proportionate share of Company stock held	3,958	19,042	255,662	18,594
Partnership interest, ending	78,917	395,070	262,979	63,573
Carry Value
Fair value of Partnership interest, beginning	557,238	471,689	697,982	397,699
Investment partnership gains (losses)	144,702	135,886	(39,356)	14,055
Investments (net of distributions)	0	(10,896)	68,725	164,078
Increase in proportionate share of Company stock held	(3,958)	(19,042)	(255,662)	(18,594)
Partnership interest, ending	$ 697,982	$ 577,637	$ 471,689	$ 557,238