Segments and Major Customers (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
Financial information of business segments
Revenues	$ 76,518	$ 57,919	$ 154,806	$ 124,785
Segment operating expenses	27,000	27,671	53,202	53,243
Segment operating income (loss)	49,518	30,248	101,604	71,542
Segment reconciling items	(29,414)	(24,504)	(58,311)	(64,357)
Operating income (loss)	20,104	5,744	43,293	7,185
Interest and other income (expense), net	(8,666)	(8,845)	(18,579)	(16,177)
Income (Loss) before income taxes	11,438	(3,101)	24,714	(8,992)
MID Segment
Financial information of business segments
Revenues	58,664	49,456	119,820	109,131
Segment operating expenses	9,517	10,344	19,437	20,228
Segment operating income (loss)	49,147	39,112	100,383	88,903
CRI Segment
Financial information of business segments
Revenues	12,771	7,914	25,674	14,797
Segment operating expenses	8,290	6,072	15,919	10,960
Segment operating income (loss)	4,481	1,842	9,755	3,837
CTO Segment
Financial information of business segments
Revenues	0	0	0	0
Segment operating expenses	4,518	6,347	8,789	13,518
Segment operating income (loss)	(4,518)	(6,347)	(8,789)	(13,518)
Other
Financial information of business segments
Revenues	5,083	549	9,312	857
Segment operating expenses	4,675	4,908	9,057	8,537
Segment operating income (loss)	$ 408	$ (4,359)	$ 255	$ (7,680)