6. Income Taxes

Our income tax provision for the periods presented and the respective effective income tax rates for such periods are as follows (in thousands, except for income tax rates):

	For the Three Months ended						For the Nine Months ended
	September 30,						September 30,
	2013			2012			2013			2012

Income tax provision	$	8,191		$	14,683		$	32,090		$	33,249

Effective income tax rate	14.0		%	21.7		%	17.3		%	17.5		%

Our provision for income taxes for each of the three-month and nine-month periods ended September 30, 2013 and 2012 were calculated based on the estimated annual effective income tax rate for the full 2013 and 2012 fiscal years. The provision for income taxes for the three and nine months ended September 30, 2013 includes an adjustment for an income tax benefit of $1.4 million for a discrete item related to a lapse in the statute of limitations. The provision for income taxes for the nine months ended September 30, 2012 includes an adjustment for an income tax benefit of $3.3 million for a discrete item related to a change in estimate in an uncertain income tax position. The actual effective income tax rate for the full 2013 fiscal year may be materially different as a result of differences between estimated versus actual results and the geographic tax jurisdictions in which the results are earned.