Employee Benefit Plans (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Contribution Plan
Defined contribution plan expenses	$ 0	$ 0	$ 0
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%