Schedule II - Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowance for doubtful accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 12,342	$ 7,340	$ 5,614
Charged/ (credited) to expense	9,458	2,632	3,635
Charged/(credited) to other accounts	(360)	4,979	0
Deductions from reserves	4,513	2,609	1,909
Balance at end of period	16,927	12,342	7,340
Valuation allowance-taxes
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	25,683	21,418	12,623
Charged/ (credited) to expense	27,410	4,265	3,405
Charged/(credited) to other accounts	0	0	5,390
Deductions from reserves	11,314	0	0
Balance at end of period	$ 41,779	$ 25,683	$ 21,418

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Amount of valuation and qualifying accounts and reserves.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SX 210.12-09)
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690

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Amount of increase in valuation and qualifying accounts and reserves from charge to cost and expense.

+ References

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Amount of increase in valuation and qualifying accounts and reserves from charge to accounts other than cost and expense.

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Amount of decrease in valuation and qualifying accounts and reserves.

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