Income Taxes

The Corporation's tax provision for interim periods is determined using an estimate of its annual effective tax rate, adjusted for discrete items. The following table summarizes the Corporation's income tax provision (dollars in thousands):



	Three Months Ended						Nine Months Ended
	September 30, 2017			October 1, 2016			September 30, 2017			October 1, 2016
Income before income taxes	$	55,955		$	50,649		$	83,541		$	113,333
Income taxes	$	18,624		$	16,837		$	27,573		$	38,652
Effective tax rate	33.3		%	33.2		%	33.0		%	34.1		%

The effective tax rate was minimally higher in the three months ended September 30, 2017. The decrease in the effective tax rate for the first nine months was principally due to the impact of adopting ASU No. 2016-09 related to stock compensation in the first quarter of 2017. The new guidance requires excess tax benefits and tax deficiencies to be recorded in the income statement when awards vest or are settled. See "Note 14. Recently Adopted Accounting Standards" in the Notes to Condensed Consolidated Financial Statements. The Corporation's tax provision for the nine months ended September 30, 2017 includes a tax benefit of $1.0 million related to the impact of this standard.