Debt (Tables)

12 Months Ended

Dec. 31, 2012

Our debt consists of the following (in thousands):



	December 31,
	2012		2011
Debt payable to 2038 at 2.6% to 8.8% in 2012 and 1.5% to 8.8% in 2011	$	2,041,709	$	2,268,668
Unsecured notes payable under credit facilities	66,000		166,500
Debt service guaranty liability	74,075		74,075
Obligations under capital leases	21,000		21,000
Industrial revenue bonds payable to 2015 at 2.4%	1,246		1,594
Total	$	2,204,030	$	2,531,837

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

The grouping of total debt between fixed and variable-rate as well as between secured and unsecured is summarized below (in thousands):



	December 31,
	2012		2011
As to interest rate (including the effects of interest rate contracts):
Fixed-rate debt	$	1,992,599	$	2,014,834
Variable-rate debt	211,431		517,003
Total	$	2,204,030	$	2,531,837
As to collateralization:
Unsecured debt	$	1,270,742	$	1,510,932
Secured debt	933,288		1,020,905
Total	$	2,204,030	$	2,531,837

Schedule Of Credit Facilities

The following table discloses certain information regarding our unsecured notes payable under our credit facilities (in thousands, except percentages):



	December 31,
	2012			2011
Unsecured revolving credit facility:
Balance outstanding	$	30,000		$	145,000
Available balance	$	467,571		$	351,571
Letter of credit outstanding under facility	$	2,429		$	3,429
Variable interest rate (excluding facility fee)	1.1		%	1.3		%
Unsecured and uncommitted overnight facility:
Balance outstanding	$	36,000		$	21,500
Variable interest rate	1.5		%	1.5		%
Both facilities:
Maximum balance outstanding during the year	$	303,100		$	330,700
Weighted average balance	$	157,447		$	151,814
Year-to-date weighted average interest rate (excluding facility fee)	1.3		%	1.5		%

Schedule Of Convertible Debt Interest Expense

Net interest expense on our 3.95% convertible senior unsecured notes is as follows (in thousands):



	Year Ended December 31,
	2012		2011		2010
Interest expense	$	1,828	$	4,218	$	5,782
Amortization of discount	—		1,334		2,191
Net interest expense	$	1,828	$	5,552	$	7,973

Principal Payments Of Debt

Scheduled principal payments on our debt (excluding $66.0 million due under our credit facilities, $21.0 million of certain capital leases, $9.9 million fair value of interest rate contracts, $.9 million net premium/(discount) on debt, $10.2 million of non-cash debt-related items, and $74.1 million debt service guaranty liability) are due during the following years (in thousands):



2013	$	349,108
2014	473,103
2015	274,707
2016	223,198
2017	140,830
2018	63,057
2019 ₍₁₎	152,211
2020	2,099
2021	957
2022	303,410
Thereafter	39,312
Total	$	2,021,992


(1)	Includes $100.0 million of our 8.1% senior unsecured notes due 2019 which may be redeemed by us at any time on or after September 2014 at our option.