Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

No definition available.

Name:	us-gaap_NumberOfOperatingSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Description of Business - Additional Information (Details) $ / shares in Units, $ in Thousands		3 Months Ended		5 Months Ended	7 Months Ended
	Feb. 06, 2017 $ / shares shares	Mar. 31, 2018 segment	Mar. 31, 2017 USD ($)	Dec. 31, 2017 segment	Jul. 31, 2017 segment
Subsidiary, Sale of Stock [Line Items]
Number of operating segments (segment) \| segment		6		6	3
IPO \| Class A Common Stock
Subsidiary, Sale of Stock [Line Items]
Shares sold in initial public offering (in shares) \| shares	35,000,000
Sale price of common stock in IPO (in dollars per share) \| $ / shares	$ 14.00
Net proceeds from initial public offering \| $			$ 456,888