Loans (Schedule of Aging of Recorded Investment in Loans) (Details) - USD ($) $ in Thousands		Jun. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, net of deferred income	[1]	$ 2,042,770	$ 2,001,415
Loans Past Due		7,585	9,435
Loans Not Past Due		2,035,185	1,991,980
Accrued interest		7,623	8,011
Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, net of deferred income	[1]	9,513	11,048
Loans Past Due		568	757
Loans Not Past Due		8,945	10,291
Receivables Acquired with Deteriorated Credit Quality | River Valley Bancorp
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, net of deferred income			262,809
Loans Past Due			4,740
Loans Not Past Due			258,069
30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		4,410	5,965
30-59 Days Past Due | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		0	130
30-59 Days Past Due | Receivables Acquired with Deteriorated Credit Quality | River Valley Bancorp
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due			2,752
60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		1,096	1,489
60-89 Days Past Due | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		0	0
60-89 Days Past Due | Receivables Acquired with Deteriorated Credit Quality | River Valley Bancorp
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due			862
90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		2,079	1,981
90 Days or More Past Due | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		568	627
90 Days or More Past Due | Receivables Acquired with Deteriorated Credit Quality | River Valley Bancorp
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due			1,126
Commercial and Industrial Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, net of deferred income	[1]	468,965	458,538
Loans Past Due		107	101
Loans Not Past Due		468,858	458,437
Commercial and Industrial Loans and Leases | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, net of deferred income	[1]	1,247	1,656
Commercial and Industrial Loans and Leases | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		51	20
Commercial and Industrial Loans and Leases | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		3	4
Commercial and Industrial Loans and Leases | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		53	77
Commercial Real Estate Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, net of deferred income	[1]	871,970	858,030
Loans Past Due		1,505	1,860
Loans Not Past Due		870,465	856,170
Commercial Real Estate Loans | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, net of deferred income	[1]	6,602	7,688
Commercial Real Estate Loans | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		1,060	1,509
Commercial Real Estate Loans | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		52	21
Commercial Real Estate Loans | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		393	330
Agricultural Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, net of deferred income	[1]	316,764	306,946
Loans Past Due		856	744
Loans Not Past Due		315,908	306,202
Agricultural Loans | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, net of deferred income	[1]	683	706
Agricultural Loans | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		110	84
Agricultural Loans | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		0	50
Agricultural Loans | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		746	610
Home Equity Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, net of deferred income	[1]	141,851	134,032
Loans Past Due		325	796
Loans Not Past Due		141,526	133,236
Home Equity Loans | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, net of deferred income		0	0
Home Equity Loans | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		234	707
Home Equity Loans | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		19	16
Home Equity Loans | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		72	73
Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, net of deferred income	[1]	61,334	60,099
Loans Past Due		637	407
Loans Not Past Due		60,697	59,692
Consumer Loans | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, net of deferred income	[1]	53	53
Consumer Loans | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		164	175
Consumer Loans | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		40	147
Consumer Loans | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		433	85
Residential Mortgage Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, net of deferred income	[1]	181,886	183,770
Loans Past Due		4,155	5,527
Loans Not Past Due		177,731	178,243
Residential Mortgage Loans | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, net of deferred income	[1]	928	945
Residential Mortgage Loans | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		2,791	3,470
Residential Mortgage Loans | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		982	1,251
Residential Mortgage Loans | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due		$ 382	$ 806

[1] Total recorded investment in loans includes $7,623 in accrued interest.