Related Parties - Issuance of Class A Shares (Details) - USD ($) $ in Thousands		3 Months Ended	9 Months Ended
	Aug. 25, 2016	Sep. 30, 2017	Sep. 30, 2017	Sep. 30, 2016	Mar. 31, 2017
Common Stock
Proceeds from sale of common stock			$ 8,332	$ 65,548
Class A common stock
Common Stock
Sale of common stock (in shares)		0	3,700,000
Special stock dividend declared per share (in shares)					0.087423
Proceeds from sale of common stock		$ 8,400
Class A common stock | JVL | Beneficial owner
Common Stock
Sale of common stock (in shares)	9,025,270
Proceeds from sale of common stock	$ 25,000
Underwriting discounts and commissions	$ 1,100
Class A common stock | Low | JVL | Beneficial owner
Common Stock
Beneficial ownership interest (as a percent)	5.00%
Ownership percentage (as a percent)	15.00%
Class A common stock | High | Beneficial owner
Common Stock
Ownership percentage (as a percent)	19.90%