General and Summary of Significant Accounting Policies Investments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Equity Securities, Amortized Cost Basis	$ 27,661
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, before Tax	0
Available-for-sale Securities	27,661
Short-term Investments [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Equity Securities, Amortized Cost Basis	14,687	$ 23,967
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, before Tax	0	0
Available-for-sale Securities	14,687	$ 23,967
Long-term Investments [Domain]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Equity Securities, Amortized Cost Basis	12,974
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, before Tax	0
Available-for-sale Securities	$ 12,974