Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accounting Policies [Abstract]
Deferred Tax Assets, Net of Valuation Allowance, Current	$ 0	$ 9,897
Deferred Revenue, Revenue Recognized	5,800	8,200	$ 9,300
Restricted Cash and Investments, Current	1,000	3,800
Noncash or Part Noncash Acquisition, Fixed Assets Acquired	1,100	6,400	32,400
Contribution of Land		700
Foreign Currency Transaction Gain (Loss), before Tax	$ 1,200	(1,000)	200
Foreign currency exchange rate, Mexican peso to U.S. dollar, percentage change in period	17.00%
Research and Development Expense	$ 2,600	4,400	$ 4,800
Deferred Tax Liabilities, Net, Noncurrent	$ 8,094	$ 15,122