Fair Value Measurement - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Assets:
Cash equivalents	$ 80,944	$ 738,090
Derivative asset	615	86
Total assets	81,559	738,176
Temporary equity-
Redeemable non-controlling interests	99,000	96,251
Level 1 [Member]
Assets:
Cash equivalents	80,944	738,090
Total assets	80,944	738,090
Level 2 [Member]
Assets:
Derivative asset	615	86
Total assets	615	86
Level 3 [Member]
Temporary equity-
Redeemable non-controlling interests	$ 99,000	$ 96,251