Employee Benefit Plans (Retirement Plan Expense) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended		12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2012	Jun. 30, 2011
Defined Benefit Plan Disclosure [Line Items]
Remeasurement charge			$ 0	$ 34	$ 34
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost (benefits earned during the period)	44	36	84	79	71	71
Interest cost	61	65	114	126	130	120
Expected return on plan assets	(75)	(70)	(144)	(146)	(141)	(132)
Settlement charges	68	0	0	68
Remeasurement charge				30	30	0
Amortization of actuarial loss	42	24	74	70	52	59
Other amortization	2	2	3	5	5	5
Net periodic defined benefit plan expense	142	57	131	232	147	123
Defined contribution plans	23	23	44	45	45	43
Total retirement plan expense	165	80	175	277	192	166
U.S. Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement charges	53
Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost (benefits earned during the period)	4	3	5	8	7	8
Interest cost	6	6	7	12	12	13
Remeasurement charge				4	4	0
Amortization of actuarial loss			5
Other amortization			(18)	(2)	(2)	(1)
Net periodic defined benefit plan expense	10	9	(1)	22	21	20
Total retirement plan expense	$ 10	$ 9	$ (1)	$ 22	$ 21	$ 20