Income Taxes

The Company accounts for income taxes under the provisions of ASU 2009-06, Income Taxes (Topic 740). The Company adjusts its effective tax rate each quarter to be consistent with the estimated annual effective tax rate. The Company also records the tax effect of unusual or infrequently occurring discrete items.

The provision for income taxes consists of the following:



	Three Months Ended September 30
	2017		2016
Income tax provision	$	18,189	$	13,595



	Nine Months Ended September 30
	2017		2016
Income tax provision	$	29,046	$	20,105

The $4.6 million increase in the income tax provision for the three months ended September 30, 2017 as compared to the three months ended September 30, 2016 was due primarily to an increase in the Company’s operating income in 2017 as compared to 2016.

The $8.9 million increase in the income tax provision for the nine months ended September 30, 2017 as compared to the nine months ended September 30, 2016 was due primarily to an increase in the Company’s operating income in 2017 as compared to 2016, which was partially offset by a $0.5 million tax benefit associated with the settlement of equity awards in 2017. The Company’s fiscal year 2017 effective tax rate is estimated to be 37%.

The Company had unrecognized tax benefits of approximately $10.2 million and $10.5 million as of September 30, 2017 and December 31, 2016, respectively. Included in the balance of unrecognized tax benefits as of September 30, 2017 and December 31, 2016 is approximately $1.9 million and $2.2 million, respectively, of tax benefits that, if recognized, would result in an adjustment to the Company’s effective tax rate. The Company does not expect its unrecognized tax benefits to change significantly within the next 12 months.