Segment Information Operating Results (Detail) - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues
Revenues					$ 132,620	$ 210,148	$ 120,028
Operating income (loss) before goodwill and other asset impairments
Operating income (loss) before goodwill and other asset impairments					(40,667)	(23,403)	2,562
Corporate and other business activities					(67,282)	(81,432)	(29,592)
Impairment of goodwill and intangible assets	$ (25,600)			$ (36,700)	(18,300)	(36,700)
Impairment of marketable securities	(29,200)	$ (7,900)	$ (22,700)		(59,781)	0	0
Interest expense					(2,455)	(3,177)	(1,725)
Other income (expense), net					14,899	7,058	7,074
Income (loss) from continuing operations before income taxes					(88,004)	(19,522)	7,911
Depreciation and amortization					23,613	24,156	19,185
Energy
Revenues
Revenues					111,397	191,608	109,624
Operating income (loss) before goodwill and other asset impairments
Operating income (loss) before goodwill and other asset impairments					2,478	29,889	12,381
Impairment of goodwill and intangible assets	$ (18,300)			$ (36,700)
Depreciation and amortization					21,904	22,530	18,392
Sports
Revenues
Revenues					21,223	18,540	10,404
Operating income (loss) before goodwill and other asset impairments
Operating income (loss) before goodwill and other asset impairments					(3,354)	(2,161)	(1,408)
Depreciation and amortization					1,709	1,626	793
Total segment operating income (loss)
Operating income (loss) before goodwill and other asset impairments
Operating income (loss) before goodwill and other asset impairments					(876)	27,728	10,973
Corporate
Operating income (loss) before goodwill and other asset impairments
Corporate and other business activities					(14,169)	(14,465)	(8,411)
Impairment of goodwill and intangible assets					$ (25,622)	$ (36,666)	$ 0