Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2012

Property and Equipment [Abstract]

Summary of property and equipment

	December 31,
	2012			2011
Computer equipment	$	3,449		$	3,254
Office equipment		319			307
Leasehold improvements		1,175			1,161
Total		4,943			4,722
Less accumulated depreciation and amortization		(3,409	)		(2,811	)
Net	$	1,534		$	1,911

Summary of depreciation and amortization expense

	Twelve months ended December 31,
	2012		2011		2010
Depreciation and amortization expense relating to:
Property and equipment	$	598	$	510	$	615
Rental equipment		3,671		2,760		1,597
Service contracts		86		—		—
Total depreciation and amortization	$	4,355	$	3,270	$	2,212