Ownership Interests in and Advances to Partner Companies and Funds - Summarized Balance Sheets for Equity Method Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Current assets	$ 357,663	$ 312,621
Non-current assets	109,454	90,469
Total assets	467,117	403,090
Current liabilities	253,692	163,016
Non-current liabilities	110,829	80,050
Shareholders’ equity	102,596	160,024
Total liabilities and shareholders’ equity	$ 467,117	$ 403,090