Fair Value Measurements (Financial Assets and Liabilities Measured at Fair Value On a Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013 U.S. government and agency obligations [Member]	Jun. 30, 2012 U.S. government and agency obligations [Member]	Jun. 30, 2013 Recurring [Member]	Mar. 31, 2013 Recurring [Member]	Jun. 30, 2013 Recurring [Member] Foreign currency swaps [Member]	Mar. 31, 2013 Recurring [Member] Foreign currency swaps [Member]	Jun. 30, 2013 Recurring [Member] Interest rate cap [Member]	Mar. 31, 2013 Recurring [Member] Interest rate cap [Member]	Jun. 30, 2013 Recurring [Member] Interest rate swap [Member]	Mar. 31, 2013 Recurring [Member] Interest rate swap [Member]	Jun. 30, 2013 Recurring [Member] Debt instruments [Member] U.S. government and agency obligations [Member]	Mar. 31, 2013 Recurring [Member] Debt instruments [Member] U.S. government and agency obligations [Member]	Jun. 30, 2013 Recurring [Member] Debt instruments [Member] Municipal debt securities [Member]	Mar. 31, 2013 Recurring [Member] Debt instruments [Member] Municipal debt securities [Member]	Jun. 30, 2013 Recurring [Member] Debt instruments [Member] Certificates Of Deposit [Member]	Mar. 31, 2013 Recurring [Member] Debt instruments [Member] Certificates Of Deposit [Member]	Jun. 30, 2013 Recurring [Member] Debt instruments [Member] Commercial paper [Member]	Mar. 31, 2013 Recurring [Member] Debt instruments [Member] Commercial paper [Member]	Jun. 30, 2013 Recurring [Member] Debt instruments [Member] Foreign government debt securities [Member]	Mar. 31, 2013 Recurring [Member] Debt instruments [Member] Foreign government debt securities [Member]	Jun. 30, 2013 Recurring [Member] Debt instruments [Member] Corporate debt securities [Member]	Mar. 31, 2013 Recurring [Member] Debt instruments [Member] Corporate debt securities [Member]	Jun. 30, 2013 Recurring [Member] Debt instruments [Member] U.S. government agency mortgage-backed securities [Member]	Mar. 31, 2013 Recurring [Member] Debt instruments [Member] U.S. government agency mortgage-backed securities [Member]	Jun. 30, 2013 Recurring [Member] Debt instruments [Member] Non-agency residential mortgage-backed securities [Member]	Mar. 31, 2013 Recurring [Member] Debt instruments [Member] Non-agency residential mortgage-backed securities [Member]	Jun. 30, 2013 Recurring [Member] Debt instruments [Member] Non-agency commercial mortgage-backed securities [Member]	Mar. 31, 2013 Recurring [Member] Debt instruments [Member] Non-agency commercial mortgage-backed securities [Member]	Jun. 30, 2013 Recurring [Member] Debt instruments [Member] Asset-backed securities [Member]	Mar. 31, 2013 Recurring [Member] Debt instruments [Member] Asset-backed securities [Member]	Jun. 30, 2013 Recurring [Member] Equity instruments [Member] Fixed income short-term sector fund [Member]	Mar. 31, 2013 Recurring [Member] Equity instruments [Member] Fixed income short-term sector fund [Member]	Jun. 30, 2013 Recurring [Member] Equity instruments [Member] Fixed income U.S. government sector fund [Member]	Mar. 31, 2013 Recurring [Member] Equity instruments [Member] Fixed income U.S. government sector fund [Member]	Jun. 30, 2013 Recurring [Member] Equity instruments [Member] Fixed income municipal sector fund [Member]	Mar. 31, 2013 Recurring [Member] Equity instruments [Member] Fixed income municipal sector fund [Member]	Jun. 30, 2013 Recurring [Member] Equity instruments [Member] Fixed income investment grade corporate sector fund [Member]	Mar. 31, 2013 Recurring [Member] Equity instruments [Member] Fixed income investment grade corporate sector fund [Member]	Jun. 30, 2013 Recurring [Member] Equity instruments [Member] Fixed income high-yield sector fund [Member]	Mar. 31, 2013 Recurring [Member] Equity instruments [Member] Fixed income high-yield sector fund [Member]	Jun. 30, 2013 Recurring [Member] Equity instruments [Member] Fixed income real return sector fund [Member]	Mar. 31, 2013 Recurring [Member] Equity instruments [Member] Fixed income real return sector fund [Member]	Jun. 30, 2013 Recurring [Member] Equity instruments [Member] Fixed income mortgage sector fund [Member]	Mar. 31, 2013 Recurring [Member] Equity instruments [Member] Fixed income mortgage sector fund [Member]	Jun. 30, 2013 Recurring [Member] Equity instruments [Member] Fixed income asset-backed securities sector fund [Member]	Mar. 31, 2013 Recurring [Member] Equity instruments [Member] Fixed income asset-backed securities sector fund [Member]	Jun. 30, 2013 Recurring [Member] Equity instruments [Member] Fixed income emerging market sector fund [Member]	Mar. 31, 2013 Recurring [Member] Equity instruments [Member] Fixed income emerging market sector fund [Member]	Jun. 30, 2013 Recurring [Member] Equity instruments [Member] Fixed income international sector fund [Member]	Mar. 31, 2013 Recurring [Member] Equity instruments [Member] Fixed income international sector fund [Member]	Jun. 30, 2013 Recurring [Member] Equity instruments [Member] Equity mutual fund - S&P 500 index [Member]	Mar. 31, 2013 Recurring [Member] Equity instruments [Member] Equity mutual fund - S&P 500 index [Member]	Jun. 30, 2013 Recurring [Member] Money market instruments [Member]	Mar. 31, 2013 Recurring [Member] Money market instruments [Member]	Jun. 30, 2013 Recurring [Member] Certificates of deposit [Member]	Mar. 31, 2013 Recurring [Member] Certificates of deposit [Member]	Jun. 30, 2013 Recurring [Member] Commercial paper [Member]	Mar. 31, 2013 Recurring [Member] Commercial paper [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Foreign currency swaps [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Foreign currency swaps [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Interest rate cap [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Interest rate cap [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Interest rate swap [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Interest rate swap [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Debt instruments [Member] U.S. government and agency obligations [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Debt instruments [Member] U.S. government and agency obligations [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Debt instruments [Member] Municipal debt securities [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Debt instruments [Member] Municipal debt securities [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Debt instruments [Member] Certificates Of Deposit [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Debt instruments [Member] Certificates Of Deposit [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Debt instruments [Member] Commercial paper [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Debt instruments [Member] Commercial paper [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Debt instruments [Member] Foreign government debt securities [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Debt instruments [Member] Foreign government debt securities [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Debt instruments [Member] Corporate debt securities [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Debt instruments [Member] Corporate debt securities [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Debt instruments [Member] U.S. government agency mortgage-backed securities [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Debt instruments [Member] U.S. government agency mortgage-backed securities [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Debt instruments [Member] Non-agency residential mortgage-backed securities [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Debt instruments [Member] Non-agency residential mortgage-backed securities [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Debt instruments [Member] Non-agency commercial mortgage-backed securities [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Debt instruments [Member] Non-agency commercial mortgage-backed securities [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Debt instruments [Member] Asset-backed securities [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Debt instruments [Member] Asset-backed securities [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Equity instruments [Member] Fixed income short-term sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Equity instruments [Member] Fixed income short-term sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Equity instruments [Member] Fixed income U.S. government sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Equity instruments [Member] Fixed income U.S. government sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Equity instruments [Member] Fixed income municipal sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Equity instruments [Member] Fixed income municipal sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Equity instruments [Member] Fixed income investment grade corporate sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Equity instruments [Member] Fixed income investment grade corporate sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Equity instruments [Member] Fixed income high-yield sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Equity instruments [Member] Fixed income high-yield sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Equity instruments [Member] Fixed income real return sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Equity instruments [Member] Fixed income real return sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Equity instruments [Member] Fixed income mortgage sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Equity instruments [Member] Fixed income mortgage sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Equity instruments [Member] Fixed income asset-backed securities sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Equity instruments [Member] Fixed income asset-backed securities sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Equity instruments [Member] Fixed income emerging market sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Equity instruments [Member] Fixed income emerging market sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Equity instruments [Member] Fixed income international sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Equity instruments [Member] Fixed income international sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Equity instruments [Member] Equity mutual fund - S&P 500 index [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Equity instruments [Member] Equity mutual fund - S&P 500 index [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Money market instruments [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Money market instruments [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Certificates of deposit [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Certificates of deposit [Member]	Jun. 30, 2013 Recurring [Member] Level 1 [Member] Commercial paper [Member]	Mar. 31, 2013 Recurring [Member] Level 1 [Member] Commercial paper [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Foreign currency swaps [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Foreign currency swaps [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Interest rate cap [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Interest rate cap [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Interest rate swap [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Interest rate swap [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Debt instruments [Member] U.S. government and agency obligations [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Debt instruments [Member] U.S. government and agency obligations [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Debt instruments [Member] Municipal debt securities [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Debt instruments [Member] Municipal debt securities [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Debt instruments [Member] Certificates Of Deposit [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Debt instruments [Member] Certificates Of Deposit [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Debt instruments [Member] Commercial paper [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Debt instruments [Member] Commercial paper [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Debt instruments [Member] Foreign government debt securities [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Debt instruments [Member] Foreign government debt securities [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Debt instruments [Member] Corporate debt securities [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Debt instruments [Member] Corporate debt securities [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Debt instruments [Member] U.S. government agency mortgage-backed securities [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Debt instruments [Member] U.S. government agency mortgage-backed securities [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Debt instruments [Member] Non-agency residential mortgage-backed securities [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Debt instruments [Member] Non-agency residential mortgage-backed securities [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Debt instruments [Member] Non-agency commercial mortgage-backed securities [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Debt instruments [Member] Non-agency commercial mortgage-backed securities [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Debt instruments [Member] Asset-backed securities [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Debt instruments [Member] Asset-backed securities [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Equity instruments [Member] Fixed income short-term sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Equity instruments [Member] Fixed income short-term sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Equity instruments [Member] Fixed income U.S. government sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Equity instruments [Member] Fixed income U.S. government sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Equity instruments [Member] Fixed income municipal sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Equity instruments [Member] Fixed income municipal sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Equity instruments [Member] Fixed income investment grade corporate sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Equity instruments [Member] Fixed income investment grade corporate sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Equity instruments [Member] Fixed income high-yield sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Equity instruments [Member] Fixed income high-yield sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Equity instruments [Member] Fixed income real return sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Equity instruments [Member] Fixed income real return sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Equity instruments [Member] Fixed income mortgage sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Equity instruments [Member] Fixed income mortgage sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Equity instruments [Member] Fixed income asset-backed securities sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Equity instruments [Member] Fixed income asset-backed securities sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Equity instruments [Member] Fixed income emerging market sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Equity instruments [Member] Fixed income emerging market sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Equity instruments [Member] Fixed income international sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Equity instruments [Member] Fixed income international sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Equity instruments [Member] Equity mutual fund - S&P 500 index [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Equity instruments [Member] Equity mutual fund - S&P 500 index [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Money market instruments [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Money market instruments [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Certificates of deposit [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Certificates of deposit [Member]	Jun. 30, 2013 Recurring [Member] Level 2 [Member] Commercial paper [Member]	Mar. 31, 2013 Recurring [Member] Level 2 [Member] Commercial paper [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Foreign currency swaps [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Foreign currency swaps [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Interest rate cap [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Interest rate cap [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Interest rate swap [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Interest rate swap [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Debt instruments [Member] U.S. government and agency obligations [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Debt instruments [Member] U.S. government and agency obligations [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Debt instruments [Member] Municipal debt securities [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Debt instruments [Member] Municipal debt securities [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Debt instruments [Member] Certificates Of Deposit [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Debt instruments [Member] Certificates Of Deposit [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Debt instruments [Member] Commercial paper [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Debt instruments [Member] Commercial paper [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Debt instruments [Member] Foreign government debt securities [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Debt instruments [Member] Foreign government debt securities [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Debt instruments [Member] Corporate debt securities [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Debt instruments [Member] Corporate debt securities [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Debt instruments [Member] U.S. government agency mortgage-backed securities [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Debt instruments [Member] U.S. government agency mortgage-backed securities [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Debt instruments [Member] Non-agency residential mortgage-backed securities [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Debt instruments [Member] Non-agency residential mortgage-backed securities [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Debt instruments [Member] Non-agency commercial mortgage-backed securities [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Debt instruments [Member] Non-agency commercial mortgage-backed securities [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Debt instruments [Member] Asset-backed securities [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Debt instruments [Member] Asset-backed securities [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Equity instruments [Member] Fixed income short-term sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Equity instruments [Member] Fixed income short-term sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Equity instruments [Member] Fixed income U.S. government sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Equity instruments [Member] Fixed income U.S. government sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Equity instruments [Member] Fixed income municipal sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Equity instruments [Member] Fixed income municipal sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Equity instruments [Member] Fixed income investment grade corporate sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Equity instruments [Member] Fixed income investment grade corporate sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Equity instruments [Member] Fixed income high-yield sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Equity instruments [Member] Fixed income high-yield sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Equity instruments [Member] Fixed income real return sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Equity instruments [Member] Fixed income real return sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Equity instruments [Member] Fixed income mortgage sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Equity instruments [Member] Fixed income mortgage sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Equity instruments [Member] Fixed income asset-backed securities sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Equity instruments [Member] Fixed income asset-backed securities sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Equity instruments [Member] Fixed income emerging market sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Equity instruments [Member] Fixed income emerging market sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Equity instruments [Member] Fixed income international sector fund [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Equity instruments [Member] Fixed income international sector fund [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Equity instruments [Member] Equity mutual fund - S&P 500 index [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Equity instruments [Member] Equity mutual fund - S&P 500 index [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Money market instruments [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Money market instruments [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Certificates of deposit [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Certificates of deposit [Member]	Jun. 30, 2013 Recurring [Member] Level 3 [Member] Commercial paper [Member]	Mar. 31, 2013 Recurring [Member] Level 3 [Member] Commercial paper [Member]	Jun. 30, 2013 Recurring [Member] Counterparty Netting & Collateral [Member]	Mar. 31, 2013 Recurring [Member] Counterparty Netting & Collateral [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents			$ 2,240	$ 4,251																																																	$ 787	$ 1,508	$ 1,125	$ 1,945	$ 328	$ 798	$ 344	$ 900																																																	$ 344	$ 900	$ 0	$ 0	$ 0	$ 0	$ 1,896	$ 3,351																																																	$ 443	$ 608	$ 1,125	$ 1,945	$ 328	$ 798	$ 0	$ 0																																																	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0
Available-for-sale securities			4,957	5,397							78	104	15	16	1,837	2,041	355	495	3	3	149	128	79	87	5	5	48	51	19	13	43	43	319	312	21	22	300	327	41	42	270	293	599	648	48	47	63	66	170	170	495	484							516	526							21	42	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	495	484							4,365	4,798							57	62	15	16	1,837	2,041	355	495	3	3	145	124	79	87	0	0	0	0	0	0	43	43	319	312	21	22	300	327	41	42	270	293	599	648	48	47	63	66	170	170	0	0							76	73							0	0	0	0	0	0	0	0	0	0	4	4	0	0	5	5	48	51	19	13	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Derivative assets			47	58	745	1,139			453	580																																																	0	0	0	0			0	0																																																	1,151	1,644	709	1,076			442	568																																																	47	75	36	63			11	12																																																	(1,151)	(1,661)
Embedded derivative assets			0	0																																																							0	0																																																							0	0																																																							0	0
Total assets			7,244	9,706																																																							860	1,426																																																							7,412	9,793																																																							123	148																																																							(1,151)	(1,661)
Derivative liabilities			(58)	(5)	(299)	(131)	0	0	(702)	(766)																																																	0	0	0	0	0	0	0	0																																																	(988)	(889)	(286)	(123)	0	0	(702)	(766)																																																	(13)	(8)	(13)	(8)	0	0	0	0																																																	943	892
Embedded derivative liabilities			(7)	(12)																																																							0	0																																																							0	0																																																							(7)	(12)
Total liabilities			(65)	(17)																																																							0	0																																																							(988)	(889)																																																							(20)	(20)																																																							943	892
Total net assets			7,179	9,689																																																							860	1,426																																																							6,424	8,904																																																							103	128																																																							(208)	(769)
Transfers from Level 2 to Level 1	$ 0	$ 53