Subsequent Event (Details) (Subsequent Event, Office space in Bedford, Massachusetts, USD $) In Millions, unless otherwise specified	1 Months Ended
	Jan. 30, 2014 item
Subsequent Event
Number of successive five-year terms for which the lease may be extended	2
Extension period of lease term	5 years
Lease obligations	$ 35.6
Minimum
Subsequent Event
Base annual rent expense	1.9
Maximum
Subsequent Event
Base annual rent expense	$ 3.9
Lease term commencing on November 1, 2014
Subsequent Event
Area of office space (in square feet)	105,874
Initial term of lease	10 years 5 months
Lease term commencing on February 1, 2015
Subsequent Event
Area of office space (in square feet)	36,799