Subsequent Events (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($) $ / shares
Subsequent Event [Line Items]
Dividends payable, amount per share | $ / shares	$ 0.21
Dividends payable, date to be paid	Mar. 15, 2018
Dividends payable, date of record	Mar. 01, 2018
2018 Share Repurchase Program
Subsequent Event [Line Items]
Share repurchase program, initial authorized amount | $	$ 300.0