Employee Benefit Plans (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Defined Contribution Plan
Current liabilities	$ 1,475,000	$ 1,489,000
Total liabilities	4,517,000	3,732,000
Plan expenses	600,000	700,000	600,000
Accrued compensation
Defined Contribution Plan
Current liabilities	1,475,000	1,290,000
Other liabilities
Defined Contribution Plan
Current liabilities		199,000
Long-term liabilities	$ 3,042,000	$ 2,243,000
Regular employees
Defined Contribution Plan
Maximum contribution per employee under the Axcelis Long-Term Investment Plan (as a percent)	35.00%
Highly compensated employees
Defined Contribution Plan
Maximum contribution per employee under the Axcelis Long-Term Investment Plan (as a percent)	16.00%