Pension and Other Post Retirement Benefit Plans - Narrative (Details) - USD ($)			12 Months Ended
	Nov. 20, 2015	Mar. 01, 2005	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Percentage of employees covered by plan			19.00%
Minimum participant attained age		55 years
Requisite service period (at least)		10 years
Percentage of the premiums paid by plan participants			100.00%
Discount rate (as a percent)			4.20%	4.50%	4.00%
Accumulated benefit obligation			$ 84,090,000	$ 71,747,000
Minimum required contribution in next fiscal year			$ 0
Amount of discretionary contributions made by employer to defined contribution plan, percent			50.00%
Maximum annual contribution percentage per employee			6.00%
Requisite service period			1000 hours
Employer percentage contribution			2.00%
Vesting period			5 years
Expense recognized in the period			$ 3,441,000	3,526,000	$ 3,396,000
Curtailment gain			2,157,000
Obligations payable			54,000	1,403,000
Post retirement plan expense			(2,437,000)	(127,000)	97,000
Fair value of plan assets			83,557,000	71,396,000	$ 77,139,000
Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets			64,064,000	52,433,000
Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets			$ 19,493,000	$ 18,963,000
Ameriana | Pentegra Plan
Defined Benefit Plan Disclosure [Line Items]
Written notice of withdrawal, period	60 days
Minimum
Defined Benefit Plan Disclosure [Line Items]
Age of plan participants			55 years
Minimum | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Maturities of debt securities			15 days	15 days
Maximum
Defined Benefit Plan Disclosure [Line Items]
Age of plan participants			65 years
Maximum | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Maturities of debt securities			8 years 11 days	9 years 15 days
Weighted Average | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Maturities of debt securities			3 years 11 months 20 days	4 years 5 months 20 days