Equity Compensation - Stock Options Outstanding by Exercise Price (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding - Weighted Average Exercise Price (in dollars per share)	$ 18.26	$ 18.78	$ 19.44	$ 21.19
Stock Options
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower limit (in dollars per shares)	12.15	12.15	13.37
Exercise price range, upper limit (in dollars per shares)	$ 33.36	$ 33.36	$ 33.36
Options Outstanding - Number Outstanding at end of period (in shares)	1,441,202
Options Outstanding - Weighted Average Remaining Contractual Life	3 years 8 months 12 days
Options Outstanding - Weighted Average Exercise Price (in dollars per share)	$ 18.26
Options Exercisable - Number Exercisable at end of period (in shares)	910,267
Options Exercisable - Weighted Average Exercise Price (in dollars per share)	$ 21.82
Stock Options | $ 12.15 – $20.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower limit (in dollars per shares)	12.15
Exercise price range, upper limit (in dollars per shares)	$ 20
Options Outstanding - Number Outstanding at end of period (in shares)	792,284
Options Outstanding - Weighted Average Remaining Contractual Life	5 years 9 months 18 days
Options Outstanding - Weighted Average Exercise Price (in dollars per share)	$ 12.75
Options Exercisable - Number Exercisable at end of period (in shares)	261,349
Options Exercisable - Weighted Average Exercise Price (in dollars per share)	$ 13.98
Stock Options | $ 20.01 – $25.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower limit (in dollars per shares)	20.01
Exercise price range, upper limit (in dollars per shares)	$ 25
Options Outstanding - Number Outstanding at end of period (in shares)	306,999
Options Outstanding - Weighted Average Remaining Contractual Life	1 year 8 months 12 days
Options Outstanding - Weighted Average Exercise Price (in dollars per share)	$ 24.45
Options Exercisable - Number Exercisable at end of period (in shares)	306,999
Options Exercisable - Weighted Average Exercise Price (in dollars per share)	$ 24.45
Stock Options | $ 25.01 – $30.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower limit (in dollars per shares)	25.01
Exercise price range, upper limit (in dollars per shares)	$ 30
Options Outstanding - Number Outstanding at end of period (in shares)	337,423
Options Outstanding - Weighted Average Remaining Contractual Life	18 days
Options Outstanding - Weighted Average Exercise Price (in dollars per share)	$ 25.33
Options Exercisable - Number Exercisable at end of period (in shares)	337,423
Options Exercisable - Weighted Average Exercise Price (in dollars per share)	$ 25.33
Stock Options | $ 30.01 – $33.36
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower limit (in dollars per shares)	30.01
Exercise price range, upper limit (in dollars per shares)	$ 33.36
Options Outstanding - Number Outstanding at end of period (in shares)	4,496
Options Outstanding - Weighted Average Remaining Contractual Life	1 year 4 months 24 days
Options Outstanding - Weighted Average Exercise Price (in dollars per share)	$ 33.36
Options Exercisable - Number Exercisable at end of period (in shares)	4,496
Options Exercisable - Weighted Average Exercise Price (in dollars per share)	$ 33.36