1st Source Corporation (Parent Company Only) Financial Information (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income:
Rental income from subsidiaries	$ 16,229	$ 18,796	$ 23,361
Other	13,651	12,660	12,665
Investment securities and other investment gains	454	580	1,399
Expenses:
Interest on subordinated notes	4,220	6,484	6,589
Interest on long-term debt and mandatorily redeemable securities	1,733	1,779	1,472
Interest on commercial paper and other short-term borrowings	211	169	300
Other	7,440	5,120	7,461
Income before income taxes	83,943	75,680	73,789
Income tax benefit	(28,985)	(26,047)	(25,594)
Net income	54,958	49,633	48,195
Parent
Income:
Rental income from subsidiaries	2,165	1,873	1,772
Other	418	499	418
Investment securities and other investment gains	626	273	237
Total income	33,638	61,384	30,602
Expenses:
Interest on subordinated notes	4,220	6,484	6,589
Interest on long-term debt and mandatorily redeemable securities	999	1,108	1,039
Interest on commercial paper and other short-term borrowings	23	17	18
Rent expense	1,698	1,635	1,483
Other	639	354	763
Total expense	7,579	9,598	9,892
Income before income taxes	26,059	51,786	20,710
Income tax benefit	1,650	2,274	2,607
Income before equity in undistributed (distributed in excess of) income of subsidiaries	27,709	54,060	23,317
Equity in (distributed in excess of) undistributed income of subsidiaries	27,249	(4,427)	24,878
Net income	54,958	49,633	48,195
Parent | Bank subsidiaries
Income:
Dividends	30,429	58,739	28,175
Expenses:
Equity in (distributed in excess of) undistributed income of subsidiaries	26,995	(4,690)	24,511
Parent | Non-bank subsidiaries
Expenses:
Equity in (distributed in excess of) undistributed income of subsidiaries	$ 254	$ 263	$ 367