Stock Option Plans and Share-Based Compensation Stock expense by P&L caption (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 11,151	$ 9,214	$ 9,499
Increase to additional paid in capital from share-based compensation	2,400	2,600	2,900
Cost of revenues [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	1,241	1,011	1,398
Research and development [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	1,359	889	1,269
Selling, general and administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 8,551	$ 7,314	$ 6,832