Cash and cash equivalents and marketable securities (Tables)

12 Months Ended

Dec. 31, 2012

Cash and cash equivalents and marketable securities

Schedule of cash and cash equivalents, and marketable securities

	December 31,
	2012		2011
Cash and cash equivalents:
Cash	$	16,677	$	12,851
Money market accounts		39,001		81,082
Marketable securities		2,460		—
Total cash and cash equivalents	$	58,138	$	93,933
Short-term marketable securities—available-for-sale:
Marketable securities	$	41,558	$	—
Total short-term marketable securities	$	41,558	$	—