Income Taxes (Tables)

12 Months Ended

Dec. 31, 2015

Income Tax Disclosure [Abstract]

Schedule of Components of Income Tax Expense (Benefit)

Components of Income Tax Expense

(Dollar amounts in thousands)

	Years Ended December 31,
	2015		2014			2013
Current income tax expense (benefit):
Federal	$	18,524	$	16,343		$	4,744
State	2,326		(1,388		)	10,504
Total	20,850		14,955			15,248
Deferred income tax expense:
Federal	12,048		7,901			31,572
State	4,849		8,314			1,895
Total	16,897		16,215			33,467
Total income tax expense	$	37,747	$	31,170		$	48,715

Schedule of Effective Income Tax Rate Reconciliation

Components of Effective Tax Rate

(Dollar amounts in thousands)

	Years Ended December 31,
	2015					2014					2013
	Amount			% of Pretax Income		Amount			% of Pretax Income		Amount			% of Pretax Income
Statutory federal income tax	$	41,934		35.0	%	$	35,167		35.0	%	$	44,807		35.0	%
(Decrease) increase in income taxes resulting from:
Tax-exempt income, net of interest     expense disallowance	(6,752		)	(5.6	)	(7,520		)	(7.5	)	(7,877		)	(6.2	)
State income tax, net of federal income tax effect	4,665			3.9		4,503			4.5		8,142			6.4
Other	(2,100		)	(1.8	)	(980		)	(1.0	)	3,643			2.9
Total	$	37,747		31.5	%	$	31,170		31.0	%	$	48,715		38.1	%

Schedule of Deferred Tax Assets and Liabilities

Deferred Tax Assets and Liabilities

(Dollar amounts in thousands)

	As of December 31,
	2015			2014
Deferred tax assets:
Allowance for credit losses	$	26,131		$	26,078
Unrealized losses on securities	18,328			18,527
Alternative minimum tax ("AMT") and other credit carryforwards	17,739			29,007
State net operating loss ("NOL") carryforwards	7,679			11,917
Equity based compensation	5,469			6,875
Non-equity based compensation	3,739			3,477
Property valuation adjustments	3,003			—
OREO	2,597			3,480
Other	8,693			7,754
Total deferred tax assets	93,378			107,115
Deferred tax liabilities:
Acquisition adjustments	(10,097		)	(10,960		)
Accrued retirement benefits	(6,065		)	(6,447		)
Cancellation of indebtedness income	(3,204		)	(4,272		)
Deferred loan fees and costs	(2,432		)	—
Other	(4,631		)	(5,045		)
Total deferred tax liabilities	(26,429		)	(26,724		)
Deferred tax valuation allowance	—			—
Net deferred tax assets	66,949			80,391
Tax effect of adjustments related to other comprehensive (loss) income	19,744			11,294
Net deferred tax assets including adjustments	$	86,693		$	91,685
Net operating loss carryforwards available to offset future taxable income:
Federal gross NOL carryforwards, begin to expire in 2035	$	922		$	—
Illinois gross NOL carryforwards, begin to expire in 2023	160,016			232,834
Indiana gross NOL carryforwards, begin to expire in 2023	11,796			17,192
Alternative minimum tax credits	17,739			25,739
Other credits, begin to expire in 2028	—			3,268

Summary of Income Tax Contingencies

Rollforward of Unrecognized Tax Benefits

(Dollar amounts in thousands)

	Years Ended December 31,
	2015			2014			2013
Beginning balance	$	912		$	279		$	—
Additions for tax positions relating to the current year	480			635			279
Additions for tax positions relating to prior years	37			—			—
Reductions for tax positions relating to prior years	(21		)	(2		)	—
Ending balance	$	1,408		$	912		$	279
Interest and penalties not included above (1):
Interest expense, net of tax effect, and penalties	$	20		$	4		$	—
Accrued interest and penalties, net of tax effect, at end of year	24			4			—

⁽¹⁾  Included in income tax expense in the Consolidated Statements of Income.