Stock Compensation - Summary of Stock Options Outstanding and Related Activity (Detail) - HGI [Member] - $ / shares shares in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Sep. 30, 2015
Warrant [Member]
Options (in shares):
Stock options outstanding at September 30, 2015	1,800
Stock options outstanding at December 31, 2015	1,800		1,800
Weighted Average Exercise Price (in dollars per share):
Granted	$ 13.13		$ 13.13
Weighted Average Grant Date Fair Value (in dollars per share):
Granted	$ 3.22		$ 3.22
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number	1,800
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price	$ 13.13
Restricted award expected to vest	$ 3.22
Employee Stock Option [Member]
Options (in shares):
Stock options outstanding at September 30, 2015	4,770
Granted	28	822
Exercised	(401)
Stock options outstanding at December 31, 2015	4,397		4,770
Stock options vested and exercisable at December 31, 2015	3,305
Weighted Average Exercise Price (in dollars per share):
Granted	$ 13.93
Exercised	8.07
Stock options outstanding at December 31, 2015	9.39		$ 9.25
Stock options vested and exercisable at December 31, 2015	8.43
Weighted Average Grant Date Fair Value (in dollars per share):
Granted	5.07
Exercised	3.12
Stock options outstanding at December 31, 2015	3.77		$ 3.70
Stock options vested and exercisable at December 31, 2015	$ 3.39
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number	4,397
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price	$ 9.39
Restricted award expected to vest	$ 3.77