4. Goodwill

Goodwill is not amortized but instead is subject to an annual impairment test or more frequently if events or changes in circumstances indicate that it may be impaired. The Company evaluates goodwill on an annual basis as of the end of the second quarter of each year. The Company has updated its evaluation of impairment indicators and has concluded that there was no impairment to the carrying value of its goodwill as of December 31, 2011.

The table below sets forth changes in carrying amount of goodwill (in thousands):


	Total
Balance as of December 31, 2010	$	65,576

Goodwill acquired		50,599

Balance as of December 31, 2011	$	116,175