Capital Stock Transactions (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Mar. 31, 2017
Capital Stock Transactions [Abstract]
Stock repurchase program, amount authorized		$ 100.0
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 55.5

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