Loans (Schedule of Risk Category of Loans) (Details) - USD ($) $ in Thousands	Sep. 30, 2016		Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	$ 2,014,003	[1],[2]	$ 1,574,027	[3],[4]
River Valley Bancorp
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	281,252
Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment [Line Items]
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)	12,084		7,555
Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	1,548,418		1,222,245
Pass | River Valley Bancorp
Financing Receivable, Recorded Investment [Line Items]
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)	188,987
Pass | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment [Line Items]
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)	1,653		1,572
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	59,555		44,193
Special Mention | River Valley Bancorp
Financing Receivable, Recorded Investment [Line Items]
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)	11,669
Special Mention | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment [Line Items]
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)	3,162		3,319
Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	30,233		22,600
Substandard | River Valley Bancorp
Financing Receivable, Recorded Investment [Line Items]
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)	8,941
Substandard | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment [Line Items]
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)	5,323		1,797
Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	0		0
Doubtful | River Valley Bancorp
Financing Receivable, Recorded Investment [Line Items]
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)	0
Doubtful | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment [Line Items]
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)	0		0
Total
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	1,638,206		1,289,038
Total | River Valley Bancorp
Financing Receivable, Recorded Investment [Line Items]
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)	209,597
Total | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment [Line Items]
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)	10,138		6,688
Commercial and Industrial Loans and Leases
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	470,381	[1]	419,176	[4]
Commercial and Industrial Loans and Leases | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment [Line Items]
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)	2,922		1,325
Commercial and Industrial Loans and Leases | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	448,350		393,270
Commercial and Industrial Loans and Leases | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	12,789		13,675
Commercial and Industrial Loans and Leases | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	9,242		12,231
Commercial and Industrial Loans and Leases | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	0		0
Commercial and Industrial Loans and Leases | Total
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	470,381		419,176
Commercial Real Estate Loans
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	864,871	[1]	620,163	[4]
Commercial Real Estate Loans | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment [Line Items]
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)	6,514		5,363
Commercial Real Estate Loans | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	817,596		586,247
Commercial Real Estate Loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	31,247		25,341
Commercial Real Estate Loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	16,028		8,575
Commercial Real Estate Loans | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	0		0
Commercial Real Estate Loans | Total
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	864,871		620,163
Agricultural Loans
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	302,954	[1]	249,699	[4]
Agricultural Loans | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment [Line Items]
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)	702		0
Agricultural Loans | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	282,472		242,728
Agricultural Loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	15,519		5,177
Agricultural Loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	4,963		1,794
Agricultural Loans | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	0		0
Agricultural Loans | Total
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	$ 302,954		$ 249,699

[1] Total recorded investment in loans includes $7,913 in accrued interest.

[2] Total recorded investment in loans includes $7,913 in accrued interest.

[3] Total recorded investment in loans includes $5,952 in accrued interest.

[4] Total recorded investment in loans includes $5,952 in accrued interest.