Subsequent Events - Additional Information (Detail) - Subsequent Event - Exchange Transaction $ in Millions	2 Months Ended
	May. 31, 2016 USD ($) shares
Subsequent Event [Line Items]
Prospective decrease in long-term debt, principal amount	$ 64.3
Prospective conversion of debt into common shares | shares	7,627,358
Prospective cash paid in debt exchange	$ 3.5
Prospective total consideration in debt exchange	9.2
Prospective reduction to carrying value of long term debt	63.7
Prospective increase in stockholders' equity	60.2
Prospective increase in common stock value	5.7
Prospective increase in gain on retirement of debt	54.5
7 3/4% Senior Notes due 2019
Subsequent Event [Line Items]
Prospective decrease in long-term debt, principal amount	47.6
9 1/2% Senior Notes due 2020
Subsequent Event [Line Items]
Prospective decrease in long-term debt, principal amount	$ 16.7