Common Stock Repurchase Programs - Additional Information (Detail) - 2016 Repurchase Program [Member] - USD ($) $ in Millions	1 Months Ended	6 Months Ended
Jan. 31, 2016	Jun. 30, 2019
Equity, Class of Treasury Stock [Line Items]
Amount authorized to be repurchased	$ 50.0
Common stock repurchased	15.4
Remaining Amount authorized to be repurchased	$ 34.6
Stock repurchased during period, shares		0

Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
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-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration