Equity (Details) (USD $)		9 Months Ended		9 Months Ended		9 Months Ended		9 Months Ended		9 Months Ended		9 Months Ended
	Mar. 31, 2012	Sep. 30, 2012 Metropolitan Life Insurance Company [Member]	Dec. 31, 2011 Metropolitan Life Insurance Company [Member]	Sep. 30, 2012 American Life Insurance Company [Member]	Dec. 31, 2011 American Life Insurance Company [Member]	Sep. 30, 2012 MetLife Insurance Company Of Connecticut [Member]	Dec. 31, 2011 MetLife Insurance Company Of Connecticut [Member]	Sep. 30, 2012 Metropolitan Tower Life Insurance Company [Member]	Dec. 31, 2011 Metropolitan Tower Life Insurance Company [Member]	Sep. 30, 2012 MetLife Investors Insurance Company [Member]	Dec. 31, 2011 MetLife Investors Insurance Company [Member]	Sep. 30, 2012 Delaware American Life Insurance Company [Member]	Dec. 31, 2011 Delaware American Life Insurance Company [Member]
Disclosure Of Dividends [Line Items]
Permitted w/o Approval			$ 1,350,000,000		$ 168,000,000		$ 504,000,000		$ 82,000,000		$ 18,000,000		$ 12,000,000
Paid		0		1,000,000,000				0		0		0
Total amount of dividend pre-approved by regulatory agency				1,500,000,000
In-kind dividend						202,000,000
Remaining dividends permitted without approval						302,000,000
Federal Reserve dividend mandate amount, per share	$ 0.74
Federal Reserve mandate amount	$ 800,000,000