Earnings per Share - Schedule of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Earnings Per Share [Abstract]
Net income attributable to continuing operations	$ 29,306	$ 23,722	$ 41,989	$ 33,038
Preferred stock dividends	(9)	(10)	(19)	(20)
Income from continuing operations available to common equity	29,297	23,712	41,970	33,018
Dividends and undistributed earnings allocated to participating securities	(48)	(68)	(67)	(96)
Income from continuing operations available to common shareholders	29,249	23,644	41,903	32,922
Net income attributable to discontinued operations	1,777	576	845	942
Preferred stock dividends	(1)	0	(1)	0
Income from discontinued operations available to common equity	1,776	576	844	942
Dividends and undistributed earnings allocated to participating securities	(3)	(2)	(2)	(3)
Income from discontinued operations available to common shareholders	$ 1,773	$ 574	$ 842	$ 939
Basic weighted-average shares outstanding (shares)	37,411	37,351	37,368	37,323
Stock options and other stock compensation (shares)	449	475	439	484
Diluted weighted-average shares outstanding (shares)	37,860	37,826	37,807	37,807
Antidilutive stock options (shares)	143	492	143	492
Earnings per share attributable to continuing operations:
Earnings per share attributable to continuing operations, basic (dollars per share)	$ 0.78	$ 0.63	$ 1.12	$ 0.88
Earnings per share attributable to continuing operations, diluted (dollars per share)	0.77	0.62	1.11	0.87
Earnings per share attributable to discontinued operations:
Earnings per share attributable to discontinued operations, basic (dollars per share)	0.05	0.02	0.02	0.03
Earnings per share attributable to discontinued operations, diluted (dollars per share)	$ 0.05	$ 0.01	$ 0.02	$ 0.03