Income Taxes (Tables)

12 Months Ended

Dec. 31, 2015

Income tax expense was as follows:



	2015			2014			2013
Current income tax expense	$	59,530		$	62,177		$	49,736
Deferred income tax expense (benefit)	(19,059		)	(4,130		)	3,279
Income tax expense, as reported	$	40,471		$	58,047		$	53,015

Income Tax Computed by Applying U.S. Federal Statutory Income Tax Rate

Reported income tax expense differed from the amounts computed by applying the U.S. federal statutory income tax rate of 35% to income before income taxes as follows:



	2015			2014			2013
Income tax expense computed at the statutory rate	$	111,930		$	117,608		$	101,808
Effect of tax-exempt interest	(70,889		)	(58,761		)	(46,535		)
Bank owned life insurance income	(1,255		)	(1,116		)	(1,086		)
Other	685			316			(1,172		)
Income tax expense, as reported	$	40,471		$	58,047		$	53,015

Schedule of Deferred Tax Assets and Liabilities

Year-end deferred taxes were as follows:



	2015			2014
Deferred tax assets:
Allowance for loan losses	$	47,551		$	34,840
Net actuarial loss on defined benefit post-retirement benefit plans	25,172			26,263
Stock-based compensation	21,246			18,839
Alternative minimum tax carryforward	10,934			—
Bonus accrual	5,832			6,118
Gain on sale of assets	2,044			2,139
Transaction costs	1,716			1,794
Partnerships	1,271			1,911
Other	4,447			5,272
Total gross deferred tax assets	120,213			97,176
Deferred tax liabilities:
Net unrealized gain on securities available for sale and effective cash flow hedging derivatives	(86,484		)	(102,626		)
Premises and equipment	(23,038		)	(20,039		)
Defined benefit post-retirement benefit plans	(14,089		)	(15,010		)
Intangible assets	(8,940		)	(6,143		)
Leases	(4,491		)	(4,952		)
Section 481(a) change in accounting method (tangible property)	(3,387		)	—
Prepaid expenses	(1,702		)	(1,639		)
Reserve for medical insurance	(211		)	(3,017		)
Other	(352		)	(341		)
Total gross deferred tax liabilities	(142,694		)	(153,767		)
Net deferred tax asset (liability)	$	(22,481	)	$	(56,591	)