Income Taxes (Tax Return Reported Federal Net Operating Losses and Tax Credits) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($)
Federal [Member]
Net operating losses	$ 551,433
Net operating losses carried forward, expiration date	Dec. 31, 2035
Foreign [Member]
Net operating losses	$ 38,001
Research Tax Credit [Member]
Tax credit	$ 16,397
Tax credit carryforwards, expiration date	Dec. 31, 2035
Alternative Minimum Tax [Member]
Tax credit	$ 94