Basis of Presentation (Earnings per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share
Net income attributable to Heartland	$ 15,160	$ 10,774	$ 30,869	$ 17,664
Preferred dividends and discount	(204)	(204)	(408)	(408)
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	$ 14,956	$ 10,570	$ 30,461	$ 17,256
Weighted average common shares outstanding for basic earnings per share	20,599	18,458	20,408	18,448
Assumed incremental common shares issued upon exercise of stock options and non-vested restricted stock units	278	289	274	291
Weighted average common shares for diluted earnings per share	20,877	18,747	20,682	18,739
Earnings per common share — basic (in dollars per share)	$ 0.73	$ 0.57	$ 1.49	$ 0.94
Earnings per common share — diluted (in dollars per share)	$ 0.72	$ 0.56	$ 1.47	$ 0.92
Number of antidilutive common stock equivalents excluded from diluted earnings per share computation	0	95	0	95