Basis of Presentation (Earnings per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share
Net income attributable to Heartland	$ 14,582	$ 11,973	$ 45,451	$ 29,637
Preferred dividends and discount	(205)	(205)	(613)	(613)
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	$ 14,377	$ 11,768	$ 44,838	$ 29,024
Weighted average common shares outstanding for basic earnings per share	20,620	18,469	20,483	18,456
Assumed incremental common shares issued upon exercise of stock options and non-vested restricted stock units	273	284	269	287
Weighted average common shares for diluted earnings per share	20,893	18,753	20,752	18,743
Earnings per common share — basic (in dollars per share)	$ 0.70	$ 0.64	$ 2.19	$ 1.57
Earnings per common share — diluted (in dollars per share)	$ 0.69	$ 0.63	$ 2.16	$ 1.55
Number of antidilutive common stock equivalents excluded from diluted earnings per share computation	0	94	0	94