Share-Based Compensation - Options Outstanding (Details) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Options Outstanding (in shares)	443,000	668,000	845,000
Options Outstanding, Weighted-Avg. Remaining Contractual Life	10 months 24 days	1 year 8 months 12 days
Options Exercisable, Exercisable (in shares)	443,000
Options Exercisable, Weighted-Avg. Exercise Price (in dollars per share)	$ 18.05
$15.98 - $18.94
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price range lower limit (in dollars per share)	15.98
Exercise price range upper limit (in dollars per share)	$ 18.94
Options Outstanding (in shares)	443,245
Options Outstanding, Weighted-Avg. Remaining Contractual Life	10 months 24 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 18.05
Options Exercisable, Exercisable (in shares)	443,245
Options Exercisable, Weighted-Avg. Exercise Price (in dollars per share)	$ 18.05