Basis of Presentation and Accounting Developments - Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue Recognition
Occupancy and equipment	$ 7,117	$ 5,933	$ 20,001	$ 16,940
Technology	15,273	13,926	45,047	36,863
Compensation	103,364	93,417	303,917	261,624
Other	6,086	5,655	19,928	16,352
Other Revenue	2,605	$ 487	7,048	$ 3,068
Difference between Revenue Guidance in Effect before and after Topic 606 \| ASU 2014-09
Revenue Recognition
Occupancy and equipment	718		1,954
Technology	315		837
Compensation	120		360
Other	177		596
Other Revenue	$ 1,330		$ 3,747

Represents occupancy and equipment expense.

No definition available.

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- Definition

The amount of expense in the period for communications and data processing expense.

+ References

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- Definition

Amount of expense for salary, wage, profit sharing; incentive and equity-based compensation; and other employee benefit.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
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- Definition

Amount of expense classified as other.

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- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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