Certain Balance Sheet Components Depreciation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Depreciation expense [Line Items]
Depreciation expense	$ 11,885	$ 13,691	$ 34,784	$ 42,118