Stockholders' Equity Shares Repurchases (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Dec. 01, 2018
Equity, Class of Treasury Stock [Line Items]
Stock Repurchased During Period, Shares	902,340
Treasury Stock Acquired, Average Cost Per Share	$ 69.46
Treasury Stock, Value, Acquired, Par Value Method	$ 62,700
Treasury Stock, Shares	1,020,328
Payments for Repurchase of Common Stock	$ 62,679	$ 51,437
2018 Stock Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Stock Repurchase Program, Authorized Amount	$ 37,300		$ 100,000