Note 12. Related-party Transactions (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Selling, general and administrative expenses	$ 37,875	[1]	$ 34,924	[2]	$ 34,244	[3]
Sister Companies, MNL and SSL | Medical Stop-Loss Business Member
Related Party Transaction, Percent Business Written Contractually Required to Cede	15.00%
Related Party Transactions, Percent Business Written Regulatory Approval to Cede Maximum	30.00%
Assumed Premiums Written by Product, Percent	24.00%		20.00%
Sister Companies, MNL and SSL | International Health and LTD Business Member
Assumed Premiums Written by Product, Percent	8.00%
Sister Companies, MNL and SSL | Fully-Insured Business Member
Assumed Premiums Written by Product, Percent	8.00%		9.00%
Sister Companies, SSL | DBL Business Member
Assumed Premiums Written by Product, Percent	20.00%
IHCAffiliatedEntityMember
Selling, general and administrative expenses	$ 1,088		$ 1,136

[1] $13,335 from related parties

[2] $11,914 from related parties

[3] $11,825 from related parties