Intangible Assets and Goodwill (Changes in Goodwill) (Detail) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Jun. 04, 2018	Jun. 03, 2018	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill				$ 1,582,806,000	$ 1,582,806,000
Accumulated impairment losses				(1,447,592,000)	(1,447,592,000)
Total	$ 0	$ 0	$ 0	$ 135,214,000	$ 135,214,000
Impact of fresh start accounting			$ (135,214,000)

Amount of fresh-start adjustment to goodwill.

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount before accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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