Organization and Significant Accounting Policies, Fair Value Measurements Using Significant Unobservable Inputs (Level 3) (Details) - Equity Securities [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Unobservable Inputs (Level 3) [Roll Forward]
Beginning balance of Level 3 investments	$ 81,881	$ 0
Transfers into Level 3 investments	0	108,009
Total gains (losses) included in accumulated other comprehensive income (loss)	22,377	(24,897)
Transfers out of Level 3 investments	(104,258)	(1,231)
Ending balance of Level 3 investments	$ 0	$ 81,881