Document and Entity Information (USD $) Share data in Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2013	Mar. 20, 2014	Jun. 30, 2013
Document and Entity Information [Abstract]
Entity Registrant Name		ING LIFE INSURANCE & ANNUITY CO
Entity Central Index Key		0000837010
Current Fiscal Year End Date		--12-31
Entity Filer Category		Non-accelerated Filer
Document Type		10-K
Document Period End Date		Dec. 31, 2013
Document Fiscal Year Focus		2013
Document Fiscal Period Focus		FY
Amendment Flag		false
Entity Common Stock, Shares Outstanding			55
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float				$ 0