Fair Value Measurements Equity Securities Without Readily Determinable Fair Values (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019
Equity Securities Without Readily Determinable Fair Value Amount [Roll Forward]
Equity Securities without Readily Determinable Fair Value, Amount	$ 0
Write-up of equity securities without readily determinable fair values	13,444	$ 0	$ 0
Equity Securities without Readily Determinable Fair Value, Amount	0	0		$ 13,000
Fair Value, Inputs, Level 3
Equity Securities Without Readily Determinable Fair Value Amount [Roll Forward]
Equity Securities without Readily Determinable Fair Value, Amount	0
Write-up of equity securities without readily determinable fair values	13,444
Equity Securities without Readily Determinable Fair Value, Amount	$ 0	$ 0		13,444
Equity Securities without Readily Determinable Fair Value, Upward Price Adjustment, Cumulative Amount				13,444
Equity Securities without Readily Determinable Fair Value, Downward Price Adjustment, Cumulative Amount				$ 0