Stock-Based Compensation Stock Options (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	1 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Jun. 30, 2019	Jun. 01, 2019
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Unrecognized pre-tax compensation expense			$ 7,000
Equity Option [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Vesting period		3 years
Employee Stock Option [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Stock options outstanding at beginning of period	10,456	10,456	10,456	10,468
Stock options forfeited / expired	(12)
Stock options outstanding at end of period	10,456	10,456
Stock options exercisable at end of period			8,293
Stock options outstanding, weighted average exercise price, beginning of period	$ 32.10	$ 32.10	$ 32.10	$ 32.11
Stock options forfeited / expired, weighted average exercise price	40.02
Stock options outstanding, weighted average exercise price, end of period	$ 32.10	$ 32.10
Stock options exercisable, Weighted Average Exercise Price			$ 30.18
Stock options outstanding, weighted average remaining contractual term	5 years 29 days
Stock options exercisable, Weighted Average Remaining Contractual Term	4 years 2 months 26 days
Stock options outstanding, intrinsic value			$ 23,343
Stock options exercisable, Intrinsic Value			$ 21,315
Unrecognized pre-tax compensation expense, period for recognition	1 year 1 month 17 days
EIP [Member] | Grants between 2013 and 2015 [Member] | Employee Stock Option [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period		7 years
EIP [Member] | Grants between 2016 and 2018 [Member] | Employee Stock Option [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period		10 years
Dow [Member] | Employee Stock Option [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period		10 years