Share Repurchase (Details) - USD ($) $ in Millions	Dec. 31, 2017	Aug. 06, 2015
Equity [Abstract]
Stock repurchase program, authorized amount		$ 100.0
Stock repurchase program, remaining authorized repurchase amount	$ 52.0

Amount remaining of a stock repurchase plan authorized.

No definition available.

Name:	us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant