Shareholders' Equity (Narrative) (Details) - USD ($) $ in Thousands, shares in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Dividends declared	$ (124,356)	$ (108,489)	$ (110,046)
Stock repurchases	$ 274,333	$ 294,566	$ 910,331
Share repurchase plan [Member]
Class of Stock [Line Items]
Shares repurchased under authorized repurchase programs	8.4	10.9	35.4
Stock repurchases	$ 274,300	$ 294,600	$ 910,300
Remaining value of stock repurchase programs authorization	525,500
Shares withheld to pay taxes [Member]
Class of Stock [Line Items]
Stock repurchases	$ 11,500	$ 7,900	$ 6,000