Stockholders' Equity - (Details)								1 Months Ended		6 Months Ended	12 Months Ended
	Jun. 30, 2018 shares	Nov. 01, 2017 USD ($) shares	Oct. 30, 2017 USD ($) $ / shares shares	Jun. 09, 2017 USD ($) shares	Jun. 05, 2017 shares	May 31, 2017 USD ($) $ / shares shares	Oct. 06, 2016 class shares	May 31, 2018 USD ($)	May 31, 2017 $ / shares shares	Jun. 30, 2018 USD ($) shares	Dec. 31, 2017 shares
Common Stock
Number of classes of common stock | class							3
Proceeds from issuance of common stock | $				$ 16,000,000
Proceeds from short-swing profit disgorgement | $										$ 557,000
M L Acquisition Company LLC And M L Related Parties
Common Stock
Proceeds from short-swing profit disgorgement | $								$ 557,000
Over allotment | October 2017 Selling Stockholders
Common Stock
Shares issued by selling stockholders			1,005,000
Class A common stock
Common Stock
Common stock, outstanding	37,007,619									37,007,619	36,749,072
Number of shares issued						4,000,000
Offering price (in dollars per share) | $ / shares						$ 27.75			$ 27.75
Proceeds from issuance of common stock | $						$ 106,600,000
Class A common stock | May 2017 Selling Stockholders
Common Stock
Offering price (in dollars per share) | $ / shares						$ 27.75			$ 27.75
Shares issued by selling stockholders				825,000		5,500,000			5,500,000
Class A common stock | CVRV Acquisition LLC
Common Stock
Redemption of common stock by selling shareholders			4,715,529
Shares of common stock redeemed for shares of common stock				648,462		4,323,083			4,323,083
Class A common stock | CVRV Acquisition II LLC
Common Stock
Shares sold that were previously held		184,669	1,283,756	176,538					1,176,917
Class A common stock | October 2017 Selling Stockholders
Common Stock
Number of shares issued			6,700,000
Offering price (in dollars per share) | $ / shares			$ 40.50
Shares issued by selling stockholders		963,799
Class A common stock | Crestview Advisors LLC
Common Stock
Shares sold that were previously held		104	715
Class A common stock | CWGS Holding, LLC and CVRV Acquisition LLC
Common Stock
Redemption of common stock by selling shareholders		678,331
Shares of common stock redeemed for shares of common stock		678,331
Class A common stock | Over allotment
Common Stock
Number of shares issued				600,000	600,000
Class A common stock | Over allotment | May 2017 Selling Stockholders
Common Stock
Shares issued by selling stockholders					825,000
Class A common stock | Over allotment | October 2017 Selling Stockholders
Common Stock
Shares issued by selling stockholders			963,799
Class B common stock
Common Stock
Common stock, outstanding	50,706,629									50,706,629	50,836,629
Consideration for redemption of shares | $		$ 0
Class B common stock | May 2017 Selling Stockholders
Common Stock
Consideration for redemption of shares | $				$ 0		$ 0
Class B common stock | CVRV Acquisition LLC
Common Stock
Number of common stock cancelled		678,331		648,462		4,323,083			4,323,083
Class B common stock | October 2017 Selling Stockholders
Common Stock
Consideration for redemption of shares | $			$ 0
Class B common stock | CWGS Holding LLC
Common Stock
Number of common stock cancelled		100,695	700,000
Class C common stock
Common Stock
Common stock, outstanding	1									1	1
CWH BR Merger | Class A common stock
Common Stock
Shares issued in acquisition							7,063,716
CWH BR Merger | Class B common stock
Common Stock
Shares cancelled							7,063,716
CWGS, LLC
Common Stock
Purchase of newly-issued common units				600,000		4,000,000			4,000,000
CWGS, LLC | Class A common stock | CVRV Acquisition LLC
Common Stock
Redemption of common stock by selling shareholders						4,323,083
Shares of common stock redeemed for shares of common stock			4,715,529
CWGS, LLC | Class A common stock | October 2017 Selling Stockholders
Common Stock
Redemption of common stock by selling shareholders			700,000
CWGS, LLC | Class A common stock | CWGS Holding, LLC and CVRV Acquisition LLC
Common Stock
Redemption of common stock by selling shareholders		100,695	700,000
Shares of common stock redeemed for shares of common stock		100,695
CWGS, LLC | Class B common stock | CVRV Acquisition LLC
Common Stock
Redemption of common stock by selling shareholders				648,462
CWGS, LLC | CWH BR Merger
Common Stock
Common stock, outstanding							7,063,716
CWH | CWGS, LLC
Common Stock
Units held	37,007,619									37,007,619	36,749,072
Ownership interest	41.70%						22.60%			41.70%	41.50%
Merged Entity | CWGS, LLC
Common Stock
Units held							7,063,716
Continuing Equity Owners | CWGS, LLC
Common Stock
Units held	51,717,209									51,717,209	51,890,495
Percentage of ownership	58.30%						77.40%			58.30%	58.50%