Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

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 505
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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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-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Name:	us-gaap_TreasuryStockValueAcquiredCostMethod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Share Repurchase Programs (Detail) - USD ($)	3 Months Ended	56 Months Ended
Share Repurchase Programs (Detail) - USD ($)	Mar. 31, 2019	Mar. 31, 2019	Aug. 31, 2014
Equity Class Of Treasury Stock [Line Items]
Stock repurchase program, authorized amount			$ 50,000,000
Purchase of common stock, shares		1,316,587
Purchase of Treasury Stock		$ 19,000,000
Program
Equity Class Of Treasury Stock [Line Items]
Purchase of common stock, shares	0