Goodwill and Intangible Assets, net - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Jun. 30, 2019	Sep. 30, 2019
Goodwill [Line Items]
Goodwill impairment charge		$ 28,025
Retirement
Goodwill [Line Items]
Goodwill impairment charge	$ 28,025	28,025
Benefit Consultants Group Inc.
Goodwill [Line Items]
Acquired finite-lived intangible assets		14,083
NTA
Goodwill [Line Items]
Acquired finite-lived intangible assets		$ 160,313

Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 20
-Section 50
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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