8. Other long-term liabilities

Other long-term liabilities consist of the following:

	2012		2011

Asset retirement obligations	$	57,816	$	52,336
Net pension liability		4,811		2,243
Deferred revenue		4,919		1,623
Other		3,828		1,657

	$	71,374	$	57,859

We assumed asset retirement obligations ("ARO") in our acquisition of the Partnership. During 2012, we also recorded asset retirement obligations related to the Canadian Hills project. We recorded these retirement obligations as we are legally required to remove these facilities at the end of their useful lives and restore the sites to their original condition. The following table represents the fair value of ARO at the date of acquisition along with the additions, reductions and accretion related to our ARO for the year ended December 31, 2012:

	2012

Asset retirement obligations beginning of year	$	52,336
Asset retirement obligation additions		3,466
Accretion of asset retirement obligations		1,590
Translation adjustments		424

Asset retirement obligations, end of year	$	57,816