Summary Of Major Accounting Policies-Treasury Stock - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2021	Dec. 12, 2014
Accounting Policies [Abstract]
Stock Repurchase Program, Number of Shares Authorized to be Repurchased			10,000,000
Treasury stock, shares	2,000,000
Treasury Stock, Value, Acquired, Cost Method	$ 100
Treasury Stock, Common, Shares		11,000,000