Amortized Costs and Fair Value of Available-for-sale Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities, Amortized Costs	$ 52,640	$ 28,869
Available-for-sale securities, Gross Unrealized Gains	285	844
Available-for-sale securities, Gross Unrealized Losses	(565)	(121)
Available-for-sale securities, Fair Value	52,360	29,592
Available-for-sale securities, Less than 12 months, Fair Value	52,360	29,592
Available-for-sale securities, Less than 12 months, Unrealized Losses	(565)	(121)
Available-for-sale securities, 12 months or more, Fair Value	0	0
Available-for-sale securities, 12 months or more, Unrealized Losses	0	0
Total, Fair Value	52,360	29,592
Total, Unrealized Losses	(565)	(121)
Certificates of deposit (non-U.S.)
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities, Amortized Costs	46,698	12,809
Available-for-sale securities, Fair Value	46,698	12,809
Available-for-sale securities, Less than 12 months, Fair Value	46,698	12,809
Available-for-sale securities, 12 months or more, Fair Value	0	0
Available-for-sale securities, 12 months or more, Unrealized Losses	0	0
Total, Fair Value	46,698	12,809
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities, Amortized Costs		11,003
Available-for-sale securities, Gross Unrealized Gains		86
Available-for-sale securities, Gross Unrealized Losses		(24)
Available-for-sale securities, Fair Value		11,065
Available-for-sale securities, Less than 12 months, Fair Value		11,065
Available-for-sale securities, Less than 12 months, Unrealized Losses		(24)
Available-for-sale securities, 12 months or more, Fair Value		0
Available-for-sale securities, 12 months or more, Unrealized Losses		0
Total, Fair Value		11,065
Total, Unrealized Losses		(24)
Corporate obligations
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities, Amortized Costs	14	13
Available-for-sale securities, Fair Value	14	13
Available-for-sale securities, Less than 12 months, Fair Value	14	13
Available-for-sale securities, 12 months or more, Fair Value	0	0
Available-for-sale securities, 12 months or more, Unrealized Losses	0	0
Total, Fair Value	14	13
Money markets
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities, Amortized Costs	37	38
Available-for-sale securities, Fair Value	37	38
Available-for-sale securities, Less than 12 months, Fair Value	37	38
Available-for-sale securities, 12 months or more, Fair Value	0	0
Available-for-sale securities, 12 months or more, Unrealized Losses	0	0
Total, Fair Value	37	38
Mutual funds
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities, Amortized Costs	86	65
Available-for-sale securities, Gross Unrealized Gains		14
Available-for-sale securities, Gross Unrealized Losses	(4)
Available-for-sale securities, Fair Value	82	79
Available-for-sale securities, Less than 12 months, Fair Value	82	79
Available-for-sale securities, Less than 12 months, Unrealized Losses	(4)
Available-for-sale securities, 12 months or more, Fair Value	0	0
Available-for-sale securities, 12 months or more, Unrealized Losses	0	0
Total, Fair Value	82	79
Total, Unrealized Losses	(4)
Other investments
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities, Amortized Costs	5,805	4,941
Available-for-sale securities, Gross Unrealized Gains	285	744
Available-for-sale securities, Gross Unrealized Losses	(561)	(97)
Available-for-sale securities, Fair Value	5,529	5,588
Available-for-sale securities, Less than 12 months, Fair Value	5,529	5,588
Available-for-sale securities, Less than 12 months, Unrealized Losses	(561)	(97)
Available-for-sale securities, 12 months or more, Fair Value	0	0
Available-for-sale securities, 12 months or more, Unrealized Losses	0	0
Total, Fair Value	5,529	5,588
Total, Unrealized Losses	$ (561)	$ (97)

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

No definition available.

Name:	us-gaap_AvailableForSaleSecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

No definition available.

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

No definition available.

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesAmortizedCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer.

+ References

No definition available.

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale in a continuous loss position.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27337-111563

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities.

+ References

No definition available.

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for less than twelve months.

+ References

No definition available.

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This item represents the aggregate fair value of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for less than twelve months.

+ References

No definition available.

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

+ References

No definition available.

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_CertificatesOfDepositMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_CorporateBondSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=arrs_CorporateObligationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_MoneyMarketFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_MutualFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_OtherDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: