Debt (Tables)

3 Months Ended

Mar. 31, 2012

Debt [Abstract]

Schedule Of Debt Outstanding

	March 31, 2012		December 31, 2011
Revolving Credit Facility, principal due at maturity in December 2016; interest payable periodically at variable interest rates. The weighted average rate at March 31, 2012 and December 31, 2011 was 1.7% and 1.0%, respectively.	$	535,000	$	265,000
6.25% Senior Notes, principal due at maturity in March 2013; interest payable semi-annually in March and September at 6.25%. The balance of these notes was redeemed in April 2012, as further described hereafter.		40,000		375,000
6.75% Senior Notes, principal due at maturity in January 2014; interest payable semi-annually in January and July at 6.75%.		150,000		150,000
7.75% Senior Notes, principal due at maturity in June 2017; interest payable semi-annually in June and December at 7.75%. These notes were issued with a $13.4 million discount, of which $9.6 million and $10.0 million was unamortized at March 31, 2012 and December 31, 2011, respectively.		455,386		455,014
	$	1,180,386	$	1,245,014