Business Combinations - Assets Acquired and Liabilities & Equity Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Jun. 01, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Assets:
Goodwill	$ 170,153		$ 6,788	$ 6,701	$ 5,260
RidgeWorth
Assets:
Cash and cash equivalents		$ 39,343
Investments		5,516
Accounts receivable		20,311
Other assets		3,003
Furniture, equipment and leasehold improvements		5,505
Intangible assets		275,700
Goodwill		163,365
Deferred taxes, net		6,590
Total Assets		1,476,026
Liabilities:
Accrued compensation and benefits		18,263
Accounts payable and accrued liabilities		11,858
Other liabilities		2,601
Noncontrolling Interests of CIP		16,181
Total Liabilities & Noncontrolling Interests		928,944
Total Net Assets Acquired		547,082
Consolidated investment products | RidgeWorth
Assets:
Cash and cash equivalents		38,261
Investments		899,274
Other assets		19,158
Liabilities:
Notes payable of CIP		770,160
Securities purchased payable and other liabilities of CIP		$ 109,881