Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

No definition available.

Name:	us-gaap_SubsequentEventLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Subsequent Event (Details) - USD ($) $ in Millions	Jan. 24, 2019	Dec. 31, 2017	Dec. 31, 2016
Subsequent Event [Line Items]
Stock Repurchase Program, Authorized Amount		$ 400.0	$ 400.0
Subsequent Event [Member]
Subsequent Event [Line Items]
Stock Repurchase Program, Authorized Amount	$ 400.0