Condensed Financial Information of Parent Company Only Disclosure: Condensed Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash and Cash Equivalents, at Carrying Value	$ 26,465	$ 22,010	$ 17,500
Short-term investments	50	6,912
Available-for-sale Securities, Debt Securities	441,912	449,487
Equity Method Investments	15,385	19,747
Other Assets	72,912	54,928
Assets, Total	1,040,623	1,134,464
Other Liabilities	56,453	55,477
Disposal Group, Including Discontinued Operation, Liabilities	0	68
Liabilities, Total	604,315	695,208
Redeemable Noncontrolling Interest, Equity, Common, Carrying Amount	2,065	0
Preferred Stock, Value, Issued	0	0
Common Stock, Value, Issued	18,625	18,620
Paid-in capital	124,538	126,468
Accumulated Other Comprehensive Income (Loss), Net of Tax	(4,598)	(6,964)
Treasury stock, at cost	(63,404)	(17,483)
Retained Earnings (Accumulated Deficit)	356,383	315,918
TOTAL IHC STOCKHOLDERS' EQUITY	431,544	436,559
NONREDEEMABLE NONCONTROLLING INTERESTS	2,699	2,697
TOTAL EQUITY	434,243	439,256	332,704	$ 309,612
TOTAL LIABILITIES AND EQUITY	1,040,623	1,134,464
Parent Company
Cash and Cash Equivalents, at Carrying Value	2,304	3,667	$ 512	$ 389
Short-term investments	0	3,500
Available-for-sale Securities, Debt Securities	27,270	48,819
Equity Method Investments	445,697	425,677
Other Assets	235	408
Assets, Total	475,506	482,071
Other Liabilities	8,886	8,732
Due to Affiliate	25,318	28,697
Accrued Income Taxes	3,411	4,236
Dividends Payable	1,583	1,082
Disposal Group, Including Discontinued Operation, Liabilities	0	68
Liabilities, Total	39,198	42,815
Redeemable Noncontrolling Interest, Equity, Common, Carrying Amount	2,065	0
Preferred Stock, Value, Issued	0	0
Common Stock, Value, Issued	18,625	18,620
Paid-in capital	124,538	126,468
Accumulated Other Comprehensive Income (Loss), Net of Tax	(4,598)	(6,964)
Treasury stock, at cost	(63,404)	(17,483)
Retained Earnings (Accumulated Deficit)	356,383	315,918
TOTAL IHC STOCKHOLDERS' EQUITY	431,544	436,559
NONREDEEMABLE NONCONTROLLING INTERESTS	2,699	2,697
TOTAL EQUITY	434,243	439,256
TOTAL LIABILITIES AND EQUITY	$ 475,506	$ 482,071