Fair Value of Financial Instruments (Details Textual)	Dec. 31, 2013	Dec. 31, 2012
Fair Value of Financial Instruments (Textual) [Abstract]
Percentage of Investment portfolio fair value pricing services or index price	87.00%	88.00%
Percentage of Invested assets in total investment portfolio level 3	2.00%

Percentage of investment portfolio fair value pricing services or index price.

No definition available.

Name:	hmn_PercentageOfInvestmentPortfolioFairValuePricingServicesOrIndexPrice
Namespace Prefix:	hmn_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant