Debt and Short-Term Borrowings - Summary of Interest Rate Swap Transaction (Detail) - Interest Rate Swap	6 Months Ended
Jun. 30, 2018 USD ($)
Derivative [Line Items]
Notional Amount	$ 200,000,000
1-month LIBOR
Derivative [Line Items]
Fixed Rate	1.9225%

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

Name:	invest_DerivativeNotionalAmount
Namespace Prefix:	invest_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant