Segments and Major Customers (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Financial information of business segments
Revenues	$ 78,288	$ 66,866
Segment operating expenses	26,202	25,572
Segment operating income (loss)	52,086	41,294
Operating income (loss)	23,189	1,441
Interest and other income (expense), net	(9,913)	(7,332)
Income (Loss) before income taxes	13,276	(5,891)
MID Segment
Financial information of business segments
Revenues	61,156	59,674
Segment operating expenses	9,920	9,884
Segment operating income (loss)	51,236	49,790
CRI Segment
Financial information of business segments
Revenues	12,903	6,883
Segment operating expenses	7,629	4,888
Segment operating income (loss)	5,274	1,995
CTO Segment
Financial information of business segments
Revenues	0	0
Segment operating expenses	4,271	7,171
Segment operating income (loss)	(4,271)	(7,171)
Other
Financial information of business segments
Revenues	4,229	309
Segment operating expenses	4,382	3,629
Segment operating income (loss)	(153)	(3,320)
Reconciling Items
Financial information of business segments
Operating income (loss)	$ (28,897)	$ (39,853)