Segment Reporting - Information about Operations in Different Segments (Parenthetical) (Detail) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended			12 Months Ended
		Jun. 30, 2014	Mar. 31, 2016	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Loss (gain) on asset disposals						$ (859)	$ 1,443	$ (46,201)
Property plant and equipment improvement		$ 1,000
Capital expenditures	[1]					228,079	102,851	321,187
Accrued Capital Expenditures of 2016 [Member]
Segment Reporting Information [Line Items]
Capital expenditures						4,000
Accrued Capital Expenditures of 2015 [Member]
Segment Reporting Information [Line Items]
Capital expenditures							14,000
Accrued Capital Expenditures of 2014 [Member]
Segment Reporting Information [Line Items]
Capital expenditures								27,000
AEA [Member]
Segment Reporting Information [Line Items]
Asset Impairment Charges			$ 32,000			43,000
ASA [Member]
Segment Reporting Information [Line Items]
Asset Impairment Charges				$ 7,000	$ 4,000	$ 12,000	4,000		$ 38,000
Loss (gain) on asset disposals				$ 3,000			$ 3,000
Property plant and equipment improvement		$ 11,000						$ 11,000

[1] Total capital expenditures represent expenditures for which cash payments were made during the period. Capital expenditures for 2016, 2015 and 2014 include $4 million, $14 million and $27 million of cash payments for accrued capital expenditures outstanding as of December 31, 2015, 2014 and 2013, respectively.