Earnings Per Share - Narrative (Details) shares in Thousands		9 Months Ended
	Oct. 11, 2016	Sep. 30, 2017 shares
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Number of shares out-of-the-money (in shares)		356
Convertible Class B Stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Common stock conversion	0.15
Date of payment of dividend to shareholders		Oct. 11, 2016