Shareholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Class of Stock [Line Items]
Cash dividends declared (usd per share)	$ 0.08	$ 0.05	$ 0.24	$ 0.15
Dividends			$ 86,296	$ 56,689
Payments for repurchase of common stock			$ 442,738	$ 155,140
Share repurchase plan
Class of Stock [Line Items]
Share repurchases (shares)			21.2	7.7
Payments for repurchase of common stock			$ 433,700	$ 147,800
Remaining value of stock repurchase programs authorization	$ 304,800		304,800
Shares withheld to pay taxes
Class of Stock [Line Items]
Payments for repurchase of common stock			$ 9,000	$ 7,200