Equity (Deficit)- Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions				3 Months Ended	6 Months Ended
	Sep. 18, 2019	Aug. 06, 2019	May 04, 2017	Sep. 30, 2019	Jun. 30, 2019	Aug. 05, 2019	Dec. 31, 2018	Dec. 21, 2018
Equity And Distributions [Line Items]
Common stock, shares authorized				300,000,000			300,000,000
Common stock, par value				$ 0.01			$ 0.0001
Treasury shares outstanding				0
Warrants outstanding				9,153,522			2,173,913
Warrant expiry date						Apr. 21, 2020
Shares repurchased during period				1,773,146
Total cost of share repurchase				$ 10.4
Average price per share repurchased				$ 5.81
Dividends declared per share		$ 0.20
Dividends paid	$ 8.2
Dividend declared date		Aug. 06, 2019
Dividend payable record date		Sep. 04, 2019
Maximum [Member]
Equity And Distributions [Line Items]
Stock repurchase authorized amount		$ 25.0
Midstates [Member]
Equity And Distributions [Line Items]
Treasury shares outstanding						205,861
Common Stock [Member]
Equity And Distributions [Line Items]
Stock repurchase authorized amount								$ 25.0
Shares repurchased during period					169,400
Average common stock price					$ 7.35
Total cost of share repurchase					$ 1.3
Warrants [Member]
Equity And Distributions [Line Items]
Warrant life period			5 years
Percentage of common shares to be issued upon exercise of warrants			8.00%
Warrant issued during period			2,173,913
Warrant exercise price			$ 42.60
Third Lien Notes Warrants [Member]
Equity And Distributions [Line Items]
Warrant exercise price						$ 22.78
Warrants outstanding						4,647,520
Unsecured Creditor Warrants [Member]
Equity And Distributions [Line Items]
Warrant exercise price						$ 43.67
Warrants outstanding						2,332,089