Income Taxes Deferred Income Tax Assets and Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred tax assets:
Accruals, reserves and other amounts not currently deductible	$ 11,346	$ 10,331
Deferred income	9,547	9,354
Tax net operating loss and credit carryforwards	9,170	6,712
Non-qualified stock compensation	6,115	5,049
Capitalized research and development	0	95
Unrealized loss on investments and other	278	208
Gross deferred tax assets	36,456	31,749
Valuation allowance	(8,999)	(7,625)
Total deferred tax assets	27,457	24,124
Deferred tax liabilities:
Long-lived assets	(5,187)	(5,351)
Total deferred tax liability	(5,187)	(5,351)
Net deferred tax assets (current and non-current)	$ 22,270	$ 18,773