Interest and Other Income - Interest Income, Net (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Statement [Abstract]
Interest income	$ 1,310	$ 1,330	$ 2,899	$ 2,124
Interest expense	(822)	(84)	(1,690)	(255)
Interest income, net	$ 488	$ 1,246	$ 1,209	$ 1,869