Capital Transactions - Information About Stock Options Outstanding (Details)	12 Months Ended
	Dec. 31, 2016 $ / shares shares
$8 to $11
Stock options, exercise price
Exercise price range, low end of range (in dollars per share)	$ 8
Exercise price range, high end of range (in dollars per share)	$ 11
Options Outstanding
Number of options outstanding (in shares) | shares	19,458
Options outstanding, Weighted Average Remaining Contractual Life	4 years 4 months 24 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 11.10
$12 to $14
Stock options, exercise price
Exercise price range, low end of range (in dollars per share)	12
Exercise price range, high end of range (in dollars per share)	$ 14
Options Outstanding
Number of options outstanding (in shares) | shares	732,048
Options outstanding, Weighted Average Remaining Contractual Life	4 years 7 months 6 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 13.43
Options Exercisable
Number of options Exercisable (in shares) | shares	205,087
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 13.26
$15 to $19
Stock options, exercise price
Exercise price range, low end of range (in dollars per share)	15
Exercise price range, high end of range (in dollars per share)	$ 19
Options Outstanding
Number of options outstanding (in shares) | shares	68,475
Options outstanding, Weighted Average Remaining Contractual Life	1 year 10 months 24 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 15.88
Options Exercisable
Number of options Exercisable (in shares) | shares	58,764
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 15.54
$8 to $19
Stock options, exercise price
Exercise price range, low end of range (in dollars per share)	8
Exercise price range, high end of range (in dollars per share)	$ 19
Options Outstanding
Number of options outstanding (in shares) | shares	819,981
Options outstanding, Weighted Average Remaining Contractual Life	4 years 4 months 24 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 13.58
Options Exercisable
Number of options Exercisable (in shares) | shares	263,851
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 13.76