6.	Income Taxes


	Three Months Ended March 31,
	2013		2012
Estimated effective income tax rate:
Continuing operations		22.4%		21.0%

Discontinued operations		21.3%		14.6%

Consolidated overall		22.4%		20.9%

The Corporation’s effective income tax rate reflects the effect of federal and state income taxes and the impact of differences in book and tax accounting arising from the net permanent benefits associated with the statutory depletion deduction for mineral reserves, the impact of foreign losses for which no tax benefit was realized and the domestic production deduction. The effective income tax rates for discontinued operations reflect the tax effects of individual operations’ transactions and are not indicative of the Corporation’s overall effective income tax rate.

The Corporation’s unrecognized tax benefits, excluding interest, correlative effects and indirect benefits, are as follows:


	Three Months Ended March 31, 2013
		(Dollars in Thousands)
Unrecognized tax benefits at beginning of period		$ 15,380
Gross increases – tax positions in prior years		4,440
Gross decreases – tax positions in prior years		(2,412)
Gross increases – tax positions in current year		389

Unrecognized tax benefits at end of period		$ 17,797

The Corporation anticipates that it is reasonably possible that unrecognized tax benefits may decrease up to $12,146,000 during the twelve months ending March 31, 2014 as a result of resolution through payments to taxing authorities and the expiration of the statute of limitations for the 2009 tax year. The majority of the decrease relates to the expected settlement of the Advance Pricing Agreement (“APA”) the Corporation has with Canada that increased the sales price charged for intercompany shipments from Canada to the United States during the years 2005 through 2011. Upon final settlement with the Canadian taxing authority, the Corporation will be allowed a corresponding refund of tax in the United States for the years 2005 through 2011 pursuant to an expected APA with the United States, which is not included in the table of unrecognized tax benefits at March 31, 2013.

At March 31, 2013, unrecognized tax benefits of $14,708,000 related to permanent income tax differences, net of federal tax expense, would have favorably affected the Corporation’s effective income tax rate if recognized. However, the unrecognized tax benefits, if recognized, would be offset by the corresponding $8,367,000 expense in the United States related to the APA settlement.