Stockholders' Equity, Share Rollforward (Details) - shares		12 Months Ended
	Aug. 02, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Class of Stock [Line Items]
Shares outstanding at beginning of year		21,036,087
Stock issued	7,590,000
Shares outstanding at end of year		21,241,504	21,036,087
Common Stock [Member]
Class of Stock [Line Items]
Shares outstanding at beginning of year		21,036,087	20,968,707	0
Shares issued from equity-based compensation		112,952	67,380	0
Reclassification		0	0	15,968,707
Stock issued		0	0	5,000,000
Shares outstanding at end of year		21,241,504	21,036,087	20,968,707
Class A Common Stock [Member]
Class of Stock [Line Items]
Shares outstanding at beginning of year		0	0	13,803,183
Reclassification		0	0	(22,421,146)
Share dividend		0	0	8,617,963
Shares outstanding at end of year		0	0	0
Class B Common Stock [Member]
Class of Stock [Line Items]
Shares outstanding at beginning of year		0	0	1,513,592
Reclassification		0	0	(1,783,858)
Restricted stock grants vested		0	0	270,266
Shares outstanding at end of year		0	0	0
Restricted Stock [Member]
Class of Stock [Line Items]
Shares issued from equity-based compensation		92,465	0	0
Restricted stock grants vested		0