Stock Compensation - Effect on Shares Outstanding and Treasury Shares (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Changes in Treasury Stock [Line Items]
Treasury stock (in shares)	795,665,646	757,657,217	744,831,978	729,547,527
Repurchases	49,482,220	30,570,129	35,480,036
Total issued (in shares)	(11,468,610)	(17,740,140)	(20,181,998)
Director
Schedule of Changes in Treasury Stock [Line Items]
Director deferred stock units issued (in shares)	(5,181)	(4,750)	(13,587)
Employee Stock Option
Schedule of Changes in Treasury Stock [Line Items]
Exercised (in shares)	(8,432,458)	(13,313,019)	(14,516,606)
Stock applied to taxes	0	0	0
Total issued (in shares)	(9,252,336)	(14,378,776)	(15,878,808)
Employee Stock Option | Director
Schedule of Changes in Treasury Stock [Line Items]
Director deferred stock units issued (in shares)	0	0	0
Restricted Stock Units (RSUs)
Schedule of Changes in Treasury Stock [Line Items]
Vested RSUs (in shares)	(2,769,994)	(4,419,464)	(5,639,666)
Stock applied to taxes	553,720	1,058,100	1,336,476
Total issued (in shares)	(2,216,274)	(3,361,364)	(4,303,190)
Restricted Stock Units (RSUs) | Director
Schedule of Changes in Treasury Stock [Line Items]
Director deferred stock units issued (in shares)	0	0	0
Employee stock purchase plan
Schedule of Changes in Treasury Stock [Line Items]
Exercised (in shares)	(819,878)
Employee stock purchase plan | Employee Stock Option
Schedule of Changes in Treasury Stock [Line Items]
Exercised (in shares)	(819,878)	(1,065,757)	(1,362,202)
Employee stock purchase plan | Restricted Stock Units (RSUs)
Schedule of Changes in Treasury Stock [Line Items]
Vested RSUs (in shares)	0	0	0