Income Taxes (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating loss carryforwards
Unrecognized tax benefits, reduction of long-term deferred tax assets, before federal tax benefit	$ 12,600,000	$ 10,600,000
Unrecognized tax benefits included in long-term income taxes payable	6,200,000	6,200,000
Portion of unrecognized tax benefits, which if recognized, would be recorded as an income tax benefit	1,600,000	2,000,000
Amount of potential unrecognized tax benefit	2,000,000
Reconciliation of the beginning and ending amounts of unrecognized income tax benefits
Balance at the beginning of the period	16,773,000	16,610,000	11,816,000
Tax positions related to current year:
Additions	1,156,000	589,000	608,000
Tax positions related to prior years:
Additions	956,000	1,521,000	4,911,000
Reductions	(91,000)	(1,947,000)	(725,000)
Balance at the end of the period	18,794,000	16,773,000	16,610,000
Undistributed earnings	7,400,000
Alternative Minimum Tax Credits
Operating loss carryforwards
Tax credit carryforwards	2,500,000
Foreign Tax Credit
Operating loss carryforwards
Tax credit carryforwards	102,000,000
Federal
Operating loss carryforwards
Operating loss carryforwards	46,200,000
Tax credit carryforwards subject to expiration	55,000,000
Income tax holiday, aggregate dollar amount	4,700,000
Federal | Research and Development as label
Operating loss carryforwards
Tax credit carryforwards	30,700,000
Federal | Excess Tax Benefits From Stock Option Tax Deductions
Operating loss carryforwards
Operating loss carryforwards	1,500,000
Tax credit carryforwards	35,600,000
State
Operating loss carryforwards
Operating loss carryforwards	302,200,000
State | Research and Development as label
Operating loss carryforwards
Tax credit carryforwards	14,900,000
State | Excess Tax Benefits From Stock Option Tax Deductions
Operating loss carryforwards
Operating loss carryforwards	$ 97,300,000