Income Taxes (Tables)

12 Months Ended

Dec. 31, 2016

Income tax expense was as follows:



	2016			2015			2014
Current income tax expense	$	48,748		$	59,530		$	62,177
Deferred income tax expense (benefit)	(11,598		)	(19,059		)	(4,130		)
Income tax expense, as reported	$	37,150		$	40,471		$	58,047

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

A reconciliation between reported income tax expense and the amounts computed by applying the U.S. federal statutory income tax rate of 35% to income before income taxes is presented in the following table. During 2016, we adopted a new accounting standard that impacted how the income tax effects associated with stock-based compensation are recognized. See Note 1 - Significant Accounting Policies for additional information.



	2016			2015			2014
Income tax expense computed at the statutory rate	$	119,494		$	111,930		$	117,608
Effect of tax-exempt interest	(75,696		)	(70,889		)	(58,761		)
Bank owned life insurance income	(1,260		)	(1,255		)	(1,116		)
Net tax benefit from stock-based compensation	(5,063		)	—			—
Other	(325		)	685			316
Income tax expense, as reported	$	37,150		$	40,471		$	58,047

Schedule of Deferred Tax Assets and Liabilities

Year-end deferred taxes were as follows:



	2016			2015
Deferred tax assets:
Allowance for loan losses	$	53,566		$	47,551
Alternative minimum tax carryforward, no expiration date	30,384			10,934
Net actuarial loss on defined benefit post-retirement benefit plans	21,956			25,172
Stock-based compensation	18,140			21,246
Bonus accrual	7,035			5,832
Gain on sale of assets	2,485			2,044
Transaction costs	1,587			1,716
Other	4,449			5,718
Total gross deferred tax assets	139,602			120,213
Deferred tax liabilities:
Premises and equipment	(33,777		)	(23,038		)
Defined benefit post-retirement benefit plans	(14,828		)	(14,089		)
Intangible assets	(11,697		)	(8,940		)
Net unrealized gain on securities available for sale and transferred securities	(8,699		)	(86,484		)
Leases	(3,042		)	(4,491		)
Section 481(a) change in accounting method (tangible property)	(1,694		)	(3,387		)
Prepaid expenses	(1,743		)	(1,702		)
Other	(436		)	(563		)
Total gross deferred tax liabilities	(75,916		)	(142,694		)
Net deferred tax asset (liability)	$	63,686		$	(22,481	)