21. Leases

The Company leases equipment, land and various other properties under non-cancelable long-term leases, expiring at various dates. Certain leases contain options that would allow the Company to extend the lease or purchase the leased asset at the end of the base lease term. In addition, the Company enters into various non-cancelable royalty lease agreements under which future minimum payments are due.

Minimum payments due in future years under these agreements in effect at December 31, 2011 are as follows:

	Operating Leases	Royalties
	(In thousands)
2012	$ 28,903	$ 24,378
2013	27,610	25,595
2014	25,119	25,810
2015	17,641	27,565
2016	9,648	24,397
Thereafter	12,640	114,371
	$ 121,561	$ 242,116

Rental expense, including amounts related to these operating leases and other shorter-term arrangements, amounted to $43.9 million in 2011, $41.6 million in 2010 and $43.3 million in 2009.

Royalties are paid to lessors either as a fixed price per ton or as a percentage of the gross sales price of the mined coal. Royalties under the majority of the Company's significant leases are paid on a percentage royalty basis. Royalty expense, including production royalties, was $349.0 million in 2011, $286.8 million in 2010 and $230.5 million in 2009.

As of December 31, 2011, certain of the Company's lease obligations were secured by outstanding surety bonds totaling $64.6 million.