Loss Per Share - Additional Information (Detail) - shares shares in Millions		12 Months Ended
	Mar. 01, 2018	Dec. 31, 2017	Dec. 31, 2015
Rights offering discount percentage			8.30%
RI Plan | Maximum
Reorganization
Increase in shares outstanding on emergence from bankruptcy proceedings		155
RI Plan | Minimum
Reorganization
Increase in shares outstanding on emergence from bankruptcy proceedings		118
RI Plan | Common Stockholders | Reorganized RELY
Reorganization
Ownership percentage on emergence from bankruptcy proceedings if common stockholders do not vote to approve the RI Plan	16.00%	16.00%
Ownership percentage on emergence from bankruptcy proceedings if common stockholders vote to approve the RI Plan	20.00%	20.00%
RI Plan | Plan Sponsor | Reorganized RELY
Reorganization
Ownership percentage on emergence from bankruptcy proceedings	49.00%	49.00%
RI Plan | Redeemable Preferred Stockholder | Reorganized RELY
Reorganization
Ownership percentage on emergence from bankruptcy proceedings if common stockholders do not vote to approve the RI Plan	35.00%	35.00%
Ownership percentage on emergence from bankruptcy proceedings if common stockholders vote to approve the RI Plan	31.00%	31.00%