Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Millions		3 Months Ended
Jan. 01, 2019	Mar. 31, 2019	Dec. 31, 2018
Significant Accounting Policies [Line Items]
Tax cuts and jobs act, reclassification from AOCI to retained earnings, tax effect	$ 27.1
Amortization expense for the deferred costs		$ 7.7	$ 6.1
Other Assets [Member]
Significant Accounting Policies [Line Items]
Deferred costs		$ 86.1	$ 83.5

Amount of deferred cost, excluding capitalized cost related to contract with customer; classified as noncurrent.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(17))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(10))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(10))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant