Securities (Other-than-temporary impairments) (Details) (USD $) In Thousands, unless otherwise specified	1 Months Ended	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013 Available-for-sale Securities [Member]	Dec. 31, 2012 Available-for-sale Securities [Member]	Mar. 31, 2013 Held-to-maturity Securities [Member]	Dec. 31, 2012 Held-to-maturity Securities [Member]	Mar. 31, 2013 Mortgage-backed Securities, Issued by US Government Sponsored Enterprises
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Non-credit related OTTI						$ 588	$ 612
OTTI write-downs included in earnings, available for sale debt securities		0	184
OTTI write-downs included in earnings, held to maturity debt securities	797	0	797
Credit related OTTI		0	981
Intent to sell OTTI		0	0
Total debt security OTTI write-downs included in earnings	981	0	981
Non-credit related impairment recorded directly to AOCI		0	683
Accretion of non-credit related impairment		(24)	0
Total recorded directly to AOCI for increase in non-credit related impairment		(24)	683
Total OTTI losses recorded on debt securities		(24)	1,664
Percentage of Heartland's mortgage-backed securities								82.00%
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Credit loss component, beginning of period		981	0	184	184	797	797
Additions: Initial credit impairments		0	981
Additions: Subsequent credit impairments		0	0
Total additions		0	981
Reductions: For securities sold		0	0
Reductions: Due to change in intent to sell or requirement to sell		0	0
Reductions: For recoveries of previous credit impairments		0	0
Total reductions		0	0
Credit loss component, end of period	$ 981	$ 981	$ 981	$ 184	$ 184	$ 797	$ 797