Senior Unsecured Notes (Tables)

9 Months Ended

Sep. 30, 2011

Senior Unsecured Notes [Abstract]

Summary Of Senior Unsecured Notes

	September 30,	December 31,	Effective
	2011	2010	Rate (1)
5.250% Senior Unsecured Notes, due January 15, 2012	$     99,939	$     99,793	5.457%
6.150% Senior Unsecured Notes, due December 15, 2012	94,315	93,946	6.894%
5.820% Senior Unsecured Notes, due March 15, 2013	25,944	25,861	6.448%
4.600% Senior Unsecured Notes, due June 15, 2013	99,951	99,930	4.742%
5.125% Senior Unsecured Notes, due February 15, 2014	200,570	200,749	5.110%
5.125% Senior Unsecured Notes, due January 15, 2015	149,694	149,625	5.297%
5.800% Senior Unsecured Notes, due January 15, 2016	200,332	200,389	5.806%
7.750% Senior Unsecured Notes, due August 15, 2019	248,318	248,158	8.017%
Total Senior Unsecured Notes	$1,119,063	$1,118,451
(1)  Includes the cost of terminated treasury lock agreements (if any), offering and other transaction costs and the discount/premium on the notes, as applicable.