Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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-Publisher FASB
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-Topic 718
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-Section 50
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Stock-Based Compensation - Shares of Restricted Stock Granted under 2010 Plan (Details) - Plan 2010 - Restricted Stock - shares	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares	75,254
Remaining Term	1 year 7 months 6 days
2015 \| Five Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term					5 years
Shares	12,023
Remaining Term					9 days
2016 \| Five Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term				5 years
Shares	15,015
Remaining Term				1 year 3 months 18 days
2017 \| Five Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term			5 years
Shares	9,972
Remaining Term			2 years 3 months 18 days
2017 \| Three Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term			3 years
Shares	4,602
Remaining Term			12 days
2018 \| Five Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term		5 years
Shares	9,655
Remaining Term		3 years 3 months 18 days
2018 \| Three Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term		3 years
Shares	1,900
Remaining Term		1 year 4 months 24 days
2018 \| Two Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term		2 years
Shares	932
Remaining Term		9 days
2018 \| Four Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term		4 years
Shares	2,068
Remaining Term		2 years 3 months 18 days
2019 \| Three Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term	3 years
Shares	16,254
Remaining Term	2 years 3 months 18 days
2019 \| Two Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term	2 years
Shares	1,484
Remaining Term	1 year 3 months 18 days
2019 \| One Year
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term	1 year
Shares	1,349
Remaining Term	9 days