Changes in Stockholders' Equity and Temporary Equity (Narrative) (Details) (USD $)	9 Months Ended			0 Months Ended	9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Jul. 31, 2012	Nov. 07, 2014 Subsequent Event [Member]	Sep. 30, 2014 Accelerated Share Repurchase [Member]	Sep. 30, 2014 Open Market Transaction [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock repurchase program, authorized amount	$ 550,000,000	$ 500,000,000	$ 50,000,000.0
Stock repurchased and retired during period	340,900,000			125,000,000	290,000,000	50,900,000
Stock repurchased and retired during period, shares				2,020,785	5,389,119	1,049,376
Stock repurchase program, outstanding balance authorized to be repurchased	$ 190,500,000