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Leases - Operating Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Operating Lease Cost
Operating lease expense	$ 3,875	$ 3,420	$ 9,477	$ 6,449
Compensation and benefits
Operating Lease Cost
Operating lease expense	130	117	260	233
Occupancy
Operating Lease Cost
Operating lease expense	3,671	3,228	9,065	6,054
Communication and technology
Operating Lease Cost
Operating lease expense	74	$ 75	$ 152	$ 162
Abandonment of leased office space | Occupancy
Operating Lease Cost
Operating lease expense	$ 1,500

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+ References

No definition available.

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- Definition

Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 55
-Paragraph 53
-URI http://asc.fasb.org/extlink&oid=77888399&loc=SL77918982-209971

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980

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