Employee Benefit Plans (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) $ / Family	Dec. 31, 2015 USD ($)	Jun. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)	Jun. 30, 2014 USD ($)
Defined Benefit Plan Disclosure [Line Items]
401(k) deferred compensation and profit sharing plan, company contributions	$ 1,121	$ 999		$ 926
Annual losses per covered family | $ / Family	150,000
Charges to earnings for self-insurance reserve	$ 3,153	2,666		2,066
Pension expense	$ 54
River Valley Bancorp | The Pentegra DB Plan
Defined Benefit Plan Disclosure [Line Items]
Total contributions under Defined Benefit Plan as reported on Form 5500			$ 163,183		$ 190,751
Multiemployer plan, maximum percentage of employer's contributions	5.00%
Postretirement Medical and Life Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Estimated future employer contributions in 2017	$ 59
Certain directors and officers
Defined Benefit Plan Disclosure [Line Items]
Accrued benefits payable	1,882	1,568
Deferred compensation expense	297	149		$ 172
Certain officers
Defined Benefit Plan Disclosure [Line Items]
Accrued benefits payable	136	267
Deferred compensation expense	$ 215	$ 77