Loans (Schedule of Risk Category of Loans) (Details) - USD ($) $ in Thousands	Sep. 30, 2017		Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	$ 2,098,726	[1]	$ 2,001,415	[2]
Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	9,099		11,048
Receivables Acquired with Deteriorated Credit Quality | River Valley Bancorp
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income			262,809
Pass
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	1,611,427		1,539,361
Pass | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	1,172		1,897
Pass | Receivables Acquired with Deteriorated Credit Quality | River Valley Bancorp
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income			175,915
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	56,741		51,673
Special Mention | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	3,060		3,121
Special Mention | Receivables Acquired with Deteriorated Credit Quality | River Valley Bancorp
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income			11,638
Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	40,418		32,480
Substandard | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	3,973		5,032
Substandard | Receivables Acquired with Deteriorated Credit Quality | River Valley Bancorp
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income			8,145
Doubtful
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	0		0
Doubtful | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	0		0
Doubtful | Receivables Acquired with Deteriorated Credit Quality | River Valley Bancorp
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income			0
Total
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	1,708,586		1,623,514
Total | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	8,205		10,050
Total | Receivables Acquired with Deteriorated Credit Quality | River Valley Bancorp
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income			195,698
Commercial and Industrial Loans and Leases
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	476,167	[1]	458,538	[2]
Commercial and Industrial Loans and Leases | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	945		1,656
Commercial and Industrial Loans and Leases | Pass
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	450,359		437,353
Commercial and Industrial Loans and Leases | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	9,374		10,454
Commercial and Industrial Loans and Leases | Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	16,434		10,731
Commercial and Industrial Loans and Leases | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	0		0
Commercial and Industrial Loans and Leases | Total
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	476,167		458,538
Commercial Real Estate Loans
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	900,937	[1]	858,030	[2]
Commercial Real Estate Loans | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	6,492		7,688
Commercial Real Estate Loans | Pass
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	862,066		814,033
Commercial Real Estate Loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	21,642		26,549
Commercial Real Estate Loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	17,229		17,448
Commercial Real Estate Loans | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	0		0
Commercial Real Estate Loans | Total
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	900,937		858,030
Agricultural Loans
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	331,482	[1]	306,946	[2]
Agricultural Loans | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	768		706
Agricultural Loans | Pass
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	299,002		287,975
Agricultural Loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	25,725		14,670
Agricultural Loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	6,755		4,301
Agricultural Loans | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	0		0
Agricultural Loans | Total
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred income	$ 331,482		$ 306,946

[1] Total recorded investment in loans includes $9,013 in accrued interest.

[2] Total recorded investment in loans includes $8,011 in accrued interest.