Basis of Presentation (Earnings per Share) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Earnings Per Share
Net income attributable to Heartland	$ 15,709us-gaap_NetIncomeLoss	$ 6,890us-gaap_NetIncomeLoss
Preferred dividends and discount	(204)	(204)
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	$ 15,505	$ 6,686
Weighted average common shares outstanding for basic earnings per share	20,215	18,437
Assumed incremental common shares issued for common stock equivalents	278	288
Weighted average common shares for diluted earnings per share	20,493	18,725
Earnings per common share — basic (in dollars per share)	$ 0.77us-gaap_EarningsPerShareBasic	$ 0.36us-gaap_EarningsPerShareBasic
Earnings per common share — diluted (in dollars per share)	$ 0.76us-gaap_EarningsPerShareDiluted	$ 0.36us-gaap_EarningsPerShareDiluted
Number of antidilutive common stock equivalents excluded from diluted earnings per share computation	0	95

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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