Description of Business, Basis of Presentation, and Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2017
Accounting Standards Update 2016-09 [Member]
Description of Business, Basis of Presentation, and Summary of Significant Accounting Policies [Line Items]
Reduction of income tax expense for excess tax benefit of share-based transactions	$ 0.9	$ 4.2

The increase (decrease) during the reporting period in the amounts payable to taxing authorities for taxes that are based on the reporting entity's earnings, net of amounts receivable from taxing authorities for refunds of overpayments or recoveries of income taxes, and in deferred and other tax liabilities and assets.

No definition available.

Name:	us-gaap_IncreaseDecreaseInIncomeTaxes
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration