Income taxes (Tables)

6 Months Ended

Jun. 30, 2013

Income Tax Disclosure [Abstract]

Schedule of summary for the activity related to unrecognized tax benefits, excluding the federal tax benefit of state tax deductions

The following table summarizes the activity related to unrecognized tax benefits, excluding the federal tax benefit of state tax deductions:

In thousands of dollars	Unrecognized Tax Benefits
Balance at Dec. 30, 2012	$	86,180
Changes in unrecognized tax benefits:
Additions based on tax positions related to the current year	3,781
Additions for tax positions of prior years	2,761
Reductions for tax positions of prior years	(25,348		)
Settlements	(277		)
Reductions due to lapse of statutes of limitations	(21,178		)
Balance at Jun. 30, 2013	$	45,919