Income Taxes Components of Deferred Tax Assets and Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred tax assets
Net operating loss carryforward	$ 61,212	$ 40,771
Research and development credits	33,484	29,659
Compensatory and other accruals	1,800	1,200
Foreign tax credits	0	7,528
Other, net	1,785	2,901
Gross deferred tax assets	98,281	82,059
Deferred tax liabilities:
Unremitted foreign earnings	7,001	29,425
Unrealized gains on investments	3,704	321
Intangible assets	6,525	8,886
Fixed assets	13,354	4,403
Gross deferred tax liabilities	30,584	43,035
Net deferred tax asset before valuation allowance	67,697	39,024
Valuation Allowance	(69,753)	(37,173)
Net deferred tax asset (liability)	$ (2,056)	$ 1,851