Fair Value Measurements (Details 3) - Level 3 - Other securities - Fair Value, Recurring - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	$ 25,725	$ 16,435	$ 39,945	$ 42,109
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings	5	(77)	(32)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	(41)	463	495
Stock and Warrants Purchases During Period	20,100	0	15,158
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	10,774	$ 23,896	$ 17,785
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)	$ 155