1st Source Corporation (Parent Company Only) Financial Information (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
ASSETS
Cash and cash equivalents	$ 80,052	$ 83,934	$ 114,327	$ 96,872
Investment securities, available-for-sale (amortized cost of $1,218 and $1,243 at December 31, 2013 and 2012, respectively)	832,700	880,764
Other investments	22,400	22,609
Trading account securities	192	146
Premises and equipment, net	46,630	45,016
Other assets	121,644	123,428
Total assets	4,722,826	4,550,693
LIABILITIES AND SHAREHOLDERS' EQUITY
Other liabilities	52,568	68,718
Long-term debt and mandatorily redeemable securities	58,335	71,021
Subordinated notes	58,764	58,764
Total liabilities	4,137,448	3,992,038
Shareholders' equity	585,378	558,655	523,918	486,383
Total liabilities and shareholders' equity	4,722,826	4,550,693
Investment securities available-for-sale, Amortized Cost	822,163	849,139
Parent
ASSETS
Cash and cash equivalents	54,348	32,603	24,415	10,799
Investment securities, available-for-sale (amortized cost of $1,218 and $1,243 at December 31, 2013 and 2012, respectively)	5,636	3,779
Other investments	1,470	1,470
Trading account securities	192	146
Premises and equipment, net	0	30
Other assets	5,475	5,693
Total assets	677,690	641,192
LIABILITIES AND SHAREHOLDERS' EQUITY
Commercial paper borrowings	12,351	4,659
Other liabilities	5,373	4,824
Long-term debt and mandatorily redeemable securities	15,824	14,290
Subordinated notes	58,764	58,764
Total liabilities	92,312	82,537
Shareholders' equity	585,378	558,655
Total liabilities and shareholders' equity	677,690	641,192
Investment securities available-for-sale, Amortized Cost	1,218	1,243
Parent | Bank subsidiaries
ASSETS
Short-term investments	500	500
Investments in subsidiary	607,695	594,851
Parent | Non-bank subsidiaries
ASSETS
Investments in subsidiary	$ 2,374	$ 2,120