Debt and leases (Tables)

12 Months Ended

Dec. 31, 2011

Debt outstanding as of December 31 was as follows:

	2011		2010
5.0% senior, unsecured notes due December 15, 2012, net of discount, including cumulative change in fair value of hedged debt: 2010 - $4,879 increase	$	-	$	284,843
5.125% senior, unsecured notes due October 1, 2014, net of discount, including cumulative change in fair value of hedged debt: 2011 - $2,788 increase		256,131		263,279
7.375% senior notes due June 1, 2015		200,000		200,000
7.0% senior notes due March 15, 2019		200,000		-
Long-term portion of debt		656,131		748,122
5.0% senior, unsecured notes due December 15, 2012, net of discount, including cumulative change in fair value of hedged debt: 2011 - $780 increase		85,575		-
Amounts drawn on credit facility		-		7,000
Total debt	$	741,706	$	755,122

Credit facility, amounts outstanding

Amounts outstanding under our credit facility for the years ended December 31 were as follows:

	2011		2010		2009
Daily average amount outstanding	$	21,655	$	49,957	$	69,267
Weighted-average interest rate		3.03%		3.20%		0.76%

Credit facility, amount available for borrowing

Amounts available for borrowing under our credit facility as of December 31, 2011 were as follows:

	Total available
Credit facility commitment	$	200,000
Outstanding letters of credit		(8,551	)
Net available for borrowing as of December 31, 2011	$	191,449

Future minimum lease payments under noncancelable operating leases

As of December 31, 2011, future minimum lease payments under noncancelable operating leases with an initial term in excess of one year were as follows:

	Operating leases
2012	$	10,249
2013		7,117
2014		2,532
2015		920
2016		772
2017		40
Total minimum lease payments	$	21,630

Composition of rent expense

The composition of rent expense for the years ended December 31 was as follows:

	2011			2010			2009
Minimum rentals	$	10,068		$	10,313		$	8,180
Sublease rentals		(144	)		(190	)		(1,677	)
Net rental expense	$	9,924		$	10,123		$	6,503