Capital Stock Repurchase Plan Transactions (Narrative) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Feb. 28, 2019
Capital Stock Repurchase Plan Transactions [Abstract]
Stock repurchase program, amount authorized		$ 150.0
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 147.4

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