Aggregate dividends declared during the period for each share of common stock outstanding.

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-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
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Amount of paid and unpaid cash dividends declared for classes of stock, for example, but not limited to, common and preferred.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 405
-Section 45
-Paragraph 2
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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.

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Weighted average number of general partnership units outstanding determined by relating the portion of time within a reporting period that general partnership units have been outstanding to the total time in that period.

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-SubTopic 10
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-Paragraph 5
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Summary of total estimated dividends to be paid (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands					12 Months Ended
	Dec. 31, 2019	Mar. 18, 2019	Mar. 07, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Dividends Payable [Line Items]
Dividends declared of $0.41 per share		$ 15,000	$ 15,000
Dividends per share (in dollars per share)		$ 0.41
Pro forma number of LLC Units outstanding (in shares)	36,293	36,285		36,286
Class A Common Stock
Dividends Payable [Line Items]
Dividends declared of $0.41 per share		$ 5,962
Pro forma number of LLC Units outstanding (in shares)		14,421			15,238	13,800
Class B Common Stock
Dividends Payable [Line Items]
Dividends declared of $0.41 per share		$ 9,038
Pro forma number of LLC Units outstanding (in shares)		21,864			21,055	22,486