Summary of Total Estimated Dividends to be Paid (Details) - USD ($) $ / shares in Units, $ in Thousands	Mar. 18, 2019	Mar. 07, 2019
Subsequent Event [Line Items]
Dividends declared of $0.41 per share	$ 15,000	$ 15,000
Dividends per share (in dollars per share)	$ 0.41
Class A Common Stock
Subsequent Event [Line Items]
Dividends declared of $0.41 per share	$ 5,962
Class B Common Stock
Subsequent Event [Line Items]
Dividends declared of $0.41 per share	$ 9,038

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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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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
-URI http://asc.fasb.org/extlink&oid=6957935&loc=d3e64057-112817

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Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

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