Share Repurchase Program - Additional Information (Detail) - Share Repurchase Program [Member] - USD ($)	1 Months Ended	9 Months Ended
Jan. 31, 2019	Sep. 30, 2017	Sep. 30, 2019
Equity Class Of Treasury Stock [Line Items]
Shares repurchase program period	2 years	15 months
Shares repurchase program authorized	$ 100,000,000.0	$ 100,000,000.0
Commencement date	2019-04	2017-10
Total shares repurchased			43,715
Cost of common stock shares repurchased			$ 11,400,000

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
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-Section 50
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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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-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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Balance Type:	debit
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