Income Tax Disclosure [Text Block] (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			35.00%
Effective Income Tax Rate Reconciliation, Subsidiary Stock Basis Write Off			$ 11,589	$ 3,903	$ 0
Effective Income Tax Rate Reconciliation, Newly Enacted Federal Statutory Income Tax Rate, Percent		21.00%
Effective Income Tax Rate Reconciliation, Newly Enacted Federal Statutory Income Tax Rate, Fiscal Year Blended Rate, Percent		28.00%
Tax Cuts and Jobs Act of 2017, Change in Tax Rate, Income Tax Expense (Benefit)			9,402
Deferred Tax Assets, Net			15,645	9,154
Income Taxes Paid (Refunds), Net			397	12,585	$ 10,974
IHCAndNonlifeSubsidiariesExcludingAmicMember | Domestic Tax Authority
Operating Loss Carryforwards	[1]		338
AMIC | Domestic Tax Authority
Operating Loss Carryforwards	[2]		144,830
Operating Loss Carryforwards, Utilization, Amount			109,055
IHC Administrative Services Inc.Member
Effective Income Tax Rate Reconciliation, Subsidiary Stock Basis Write Off			11,589
Income Tax Deduction On Subsidiary Stock Basis Write Off			33,110
Health Plan Administrators Subsidiary Member
Effective Income Tax Rate Reconciliation, Subsidiary Stock Basis Write Off			3,903
Income Tax Deduction On Subsidiary Stock Basis Write Off			11,150
AMICSubsidiariesMember
Deferred Tax Assets, Net			18,602	$ 15,427
ValuationAllowance Deferred Tax Asset Change In Amount Due To Change In Projected NOL Utilization			(20,261)
ValuationAllowance Deferred Tax Asset Change In Amount Due To Change In Enacted Tax Rate			$ (6,263)

[1] Which expire in 2037.

[2] Which expire in varying amounts through 2034, a significant portion expires in 2020.