Note Discontinued Operations and restructuring plan - Additional information (Detail) - USD ($) $ in Thousands	3 Months Ended		18 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Liabilities from discontinued operations	$ 1,815		$ 1,815
Assets from discontinued operations	0		0
Discontinued Operations
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Income Loss From Discontinued Operations Net Of Tax	0	$ 1,341
Continuing Operations
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Restructuring Charges	0	10,753	$ 45,100
Professional fees	$ 75,459	75,528
Continuing Operations | Restructuring Charges Member
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Professional fees		$ 9,400