Supplementary Balance Sheet Information - Significant Components of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Uncategorized [Abstract]
Prepaid expenses	$ 55,076	$ 37,961
Supplies inventory	13,478	15,114
Income taxes receivable		51,322
Other	55,564	49,802
Total	$ 124,118	$ 154,199