Discontinued Operations (Results of Operations from Discontinued Operations) (Detail) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of assets, disposal group, before benefit from income taxes									$ (12,922,000)	$ 0	$ 0
(Provision for) benefit from income taxes									4,500,000	(6,200,000)	(15,600,000)
Net income (loss) from discontinued operations	(1,300,000)	(9,300,000)	(1,100,000)	2,500,000	1,600,000	1,000,000	1,100,000	4,800,000	(9,223,000)	8,516,000	24,257,000
DirectStar [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue									60,200,000	148,500,000	143,300,000
Income (loss) from operations before (provision for) benefit from income taxes									6,200,000	22,100,000	42,900,000
Loss on disposal before provision for income taxes									(200,000)	0	0
(Provision for) benefit from income taxes									(2,300,000)	(8,400,000)	(16,300,000)
Net income (loss) from discontinued operations									3,700,000	13,700,000	26,600,000
Globetec [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue									18,800,000	29,200,000	21,700,000
Income (loss) from operations before (provision for) benefit from income taxes									(7,000,000)	(7,400,000)	(3,000,000)
Impairment of assets, disposal group, before benefit from income taxes									(12,700,000)	0	0
(Provision for) benefit from income taxes									6,800,000	2,200,000	(700,000)
Net income (loss) from discontinued operations									$ (12,900,000)	$ (5,200,000)	$ (2,300,000)