Financial Instruments and Guarantees with Off-Balance-Sheet Risk (Tables)

12 Months Ended

Dec. 31, 2012

Financial Instruments And Guarantees With Off Balance Sheet Risk Disclosure [Abstract]

Letters of credit, bank guarantees, surety bonds and corporate guarantees

As of December 31, 2012, the Company had the following financial instruments with off-balance-sheet risk:

	Reclamation Obligations		Lease Obligations		Workers’ Compensation Obligations		Other(1)		Total
	(Dollars in millions)
Self bonding	$	1,275.8	$	—	$	—	$	—	$	1,275.8
Surety bonds	316.5		105.3		29.4		8.8		460.0
Bank guarantees	255.1		—		—		175.3		430.4
Letters of credit	—		—		24.1		81.3		105.4
	$	1,847.4	$	105.3	$	53.5	$	265.4	$	2,271.6

⁽¹⁾  Other includes the $79.7 million in letters of credit described below and an additional $185.7 million in bank guarantees, letters of credit and surety bonds related to collateral for surety companies, road maintenance, performance guarantees and other operations.