Debt (Tables)

3 Months Ended

Mar. 31, 2012

Debt [Abstract]

Schedule Of Debt

	March 31,		December 31,
	2012		2011
Debt payable to 2038 at 1.5% to 8.8%	$	2,230,979	$	2,268,668
Debt service guaranty liability		74,075		74,075
Unsecured notes payable under revolving credit facilities		170,000		166,500
Obligations under capital leases		21,000		21,000
Industrial revenue bonds payable to 2015 at 2.4%		1,507		1,594
Total	$	2,497,561	$	2,531,837

Grouping Of Debt Between Fixed And Variable As Well As Secured And Unsecured

	March 31,		December 31,
	2012		2011
As to interest rate (including the effects of interest rate contracts):
Fixed-rate debt	$	1,981,494	$	2,014,834
Variable-rate debt		516,067		517,003
Total	$	2,497,561	$	2,531,837
As to collateralization:
Unsecured debt	$	1,513,184	$	1,510,932
Secured debt		984,377		1,020,905
Total	$	2,497,561	$	2,531,837

Revolving Credit Facilities

	March 31,			December 31,
	2012			2011
Unsecured revolving credit facility:
Balance outstanding	$	170,000		$	145,000
Available balance		326,571			351,571
Letter of credit outstanding under facility		3,429			3,429
Variable interest rate (excluding facility fee)		1.3	%		1.3	%
Unsecured and uncommitted overnight facility:
Balance outstanding	$	-		$	21,500
Variable interest rate		-			1.5	%
Both facilities:
Maximum balance outstanding during the year	$	180,000		$	330,700
Weighted average balance		142,932			151,814
Weighted average interest rate (excluding facility fee)		1.3	%		1.5	%

Principal Payments Of Debt

2012 remaining	$	460,652
2013		315,211
2014		473,968
2015		243,790
2016		231,661
2017		142,096
2018		64,441
2019		153,724
2020		3,746
2021		2,763
Thereafter (1)		118,575
Total	$	2,210,627

(1) Includes $54.1 million of our 3.95% convertible senior unsecured notes outstanding due 2026, which may be called by us at any time and have future put options in 2016 and 2021.