Regulatory Matters (Tables)

12 Months Ended

Dec. 31, 2017

Regulatory Capital Requirements [Abstract]

Schedule of actual and required capital amounts and ratios

The following table shows the actual and required capital amounts and ratios for 1st Source Corporation and 1st Source Bank as of December 31, 2017 and 2016.



	Actual				Minimum Capital Adequacy				Minimum Capital Adequacy with Capital Buffer⁽¹⁾				To Be Well Capitalized Under Prompt Corrective Action Provisions
(Dollars in thousands)	Amount		Ratio		Amount		Ratio		Amount		Ratio		Amount		Ratio
2017
Total Capital (to Risk-Weighted Assets):
1st Source Corporation	$	764,853	14.70	%	$	416,174	8.00	%	$	481,201	9.25	%	$	520,218	10.00	%
1st Source Bank	696,248		13.36		416,902		8.00		482,043		9.25		521,127		10.00
Tier 1 Capital (to Risk-Weighted Assets):
1st Source Corporation	699,420		13.44		312,131		6.00		377,158		7.25		416,174		8.00
1st Source Bank	630,702		12.10		312,676		6.00		377,817		7.25		416,902		8.00
Common Equity Tier 1 Capital (to Risk-Weighted Assets):
1st Source Corporation	642,420		12.35		234,098		4.50		299,125		5.75		338,142		6.50
1st Source Bank	630,702		12.10		234,507		4.50		299,648		5.75		338,733		6.50
Tier 1 Capital (to Average Assets):
1st Source Corporation	699,420		12.17		229,890		4.00		N/A		N/A		287,362		5.00
1st Source Bank	630,702		10.98		229,789		4.00		N/A		N/A		287,236		5.00
2016
Total Capital (to Risk-Weighted Assets):
1st Source Corporation	$	713,498	15.12	%	$	377,432	8.00	%	$	406,919	8.625	%	$	471,791	10.00	%
1st Source Bank	662,531		14.06		377,014		8.00		406,468		8.625		471,267		10.00
Tier 1 Capital (to Risk-Weighted Assets):
1st Source Corporation	651,006		13.80		283,074		6.00		312,561		6.625		377,432		8.00
1st Source Bank	603,022		12.80		282,760		6.00		312,214		6.625		377,014		8.00
Common Equity Tier 1 Capital (to Risk-Weighted Assets):
1st Source Corporation	594,006		12.59		212,306		4.50		241,793		5.125		306,664		6.50
1st Source Bank	603,022		12.80		212,070		4.50		241,524		5.125		306,324		6.50
Tier 1 Capital (to Average Assets):
1st Source Corporation	651,006		12.11		215,115		4.00		N/A		N/A		268,893		5.00
1st Source Bank	603,022		11.22		214,949		4.00		N/A		N/A		268,686		5.00

(1) The capital conservation buffer requirement will be phased in over three years beginning in 2016. The capital buffer requirement effectively raises the minimum required common equity Tier 1 capital ratio to 7.0%, the Tier 1 capital ratio to 8.5%, and the total capital ratio to 10.5% on a fully phased-in basis.