Commitment and contingencies.

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- Definition

Letter of credit expiration year.

+ References

No definition available.

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- Definition

Number of non-cancelable operating lease agreements.

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No definition available.

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- Definition

Operating leases future minimum payments due in Seven years.

+ References

No definition available.

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- Definition

Operating leases future minimum payments due in six years.

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No definition available.

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- Definition

Sublease expiration month and year.

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No definition available.

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- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

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- Definition

Amount of required minimum rental payments for leases having an initial or remaining non-cancelable letter-terms in excess of one year.

+ References

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- Definition

Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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- Definition

Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income.

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- Definition

The cash inflow from bank borrowing during the year.

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- Definition

Amount of sublease income excluding finance and operating lease expense.

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Commitments and Contingencies - Additional Information (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) Agreement	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Commitment And Contingencies [Line Items]
Number of non-cancelable operating lease agreements \| Agreement			4
2019	$ 3,569,000		$ 3,569,000
2020	4,223,000		4,223,000
2021	3,981,000		3,981,000
2022	4,095,000		4,095,000
2023	4,214,000		4,214,000
2024	3,039,000		3,039,000
Total minimum lease payments	24,157,000		24,157,000
Rent expense	1,100,000	$ 900,000	3,000,000	$ 2,800,000
Letters of credit outstanding, amount	600,000		$ 600,000		$ 800,000
Letter of credit expiration period			2019
Letter of Credit
Commitment And Contingencies [Line Items]
Amounts drawn against letters of credit			$ 0		$ 0
Office Space in San Francisco
Commitment And Contingencies [Line Items]
Sublease income		$ 300,000		$ 800,000
Sublease expiration period			2017-11
Total minimum lease payments	15,700,000		$ 15,700,000
Office Space in San Francisco \| Minimum
Commitment And Contingencies [Line Items]
2019	1,000,000		1,000,000
2020	1,000,000		1,000,000
2021	1,000,000		1,000,000
2022	1,000,000		1,000,000
2023	1,000,000		1,000,000
2024	1,000,000		1,000,000
Office Space in San Francisco \| Maximum
Commitment And Contingencies [Line Items]
2019	2,200,000		2,200,000
2020	2,200,000		2,200,000
2021	2,200,000		2,200,000
2022	2,200,000		2,200,000
2023	2,200,000		2,200,000
2024	2,200,000		2,200,000
Office Space in Chicago
Commitment And Contingencies [Line Items]
Total minimum lease payments	5,100,000		5,100,000
Office Space in Chicago \| Minimum
Commitment And Contingencies [Line Items]
2019	500,000		500,000
2020	500,000		500,000
2021	500,000		500,000
2022	500,000		500,000
2023	500,000		500,000
2024	500,000		500,000
Office Space in Chicago \| Maximum
Commitment And Contingencies [Line Items]
2019	1,000,000		1,000,000
2020	1,000,000		1,000,000
2021	1,000,000		1,000,000
2022	1,000,000		1,000,000
2023	1,000,000		1,000,000
2024	$ 1,000,000		$ 1,000,000