Shareholders' Equity (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 17, 2018	Dec. 31, 2017
Equity, Class of Treasury Stock [Line Items]
Common stock, authorized	1,200,000,000		1,200,000,000
Preferred shares, authorized	20,000,000		20,000,000
2018 Program [Member]
Equity, Class of Treasury Stock [Line Items]
Amount approved to repurchase, shares, maximum		$ 20,000