Parent Company Only Condensed Financial Statements (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								9 Months Ended	12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Sep. 30, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash and Cash Equivalents, at Carrying Value	$ 210,569				$ 116,370					$ 210,569	$ 116,370	$ 188,143
Total assets	3,170,197				3,325,786					3,170,197	3,325,786	3,377,779
Subordinated debentures	62,581				85,081					62,581	85,081
Notes payable	10,500				11,700					10,500	11,700
Stockholders' Equity Attributable to Parent	279,705				235,745					279,705	235,745		179,801
Liabilities and Equity	3,170,197				3,325,786					3,170,197	3,325,786
Subordinated debentures										3,019	4,082	4,515
Interest Expense	4,064	4,309	4,753	5,011	5,295	5,390	5,896	6,586		18,137	23,167	30,155
Income tax expense	860	4,713	6,024	5,379	2,102	4,396	4,746	3,290		16,976	14,534	12,802
Net income	3,621	8,410	11,033	10,040	5,415	7,930	8,766	6,185	28,296	33,104	28,296	25,423
Net income available to common shareholders	3,621	8,410	11,033	10,040	4,153	7,282	8,122	5,544	25,101	33,104	25,101	22,899
Share-based compensation										5,048	2,537	1,466
Excess Tax Benefit (Tax Deficiency) from Share-based Compensation, Operating Activities										222	66	(53)
Net Cash Provided by (Used in) Operating Activities										29,308	37,373	27,131
Net Cash Provided by (Used in) Investing Activities										176,084	(6,282)	394
Proceeds from notes payable										0	12,000	0
Repayments of notes payable	(500)									(1,200)	(300)	0
Debt issuance costs										0	(45)	0
Cash dividends paid on common stock										(3,946)	(3,757)	(3,577)
Excess tax benefit of share-based compensation										222	66	(53)
Payments for the repurchase of preferred stock										0	(35,000)	0
Cash dividends paid on preferred stock										0	(1,711)	(1,750)
Issuance of common stock										1	3	32,612
Repurchase of common stock warrants										(1,006)	0	0
Proceeds from the issuance of equity instruments										2,264	1,558	1,468
Net Cash Provided by (Used in) Financing Activities										(111,193)	(102,864)	(133,050)
Cash and Cash Equivalents, Period Increase (Decrease)										94,199	(71,773)	(105,525)
Cash and cash equivalents, beginning of period				116,370				188,143	188,143	116,370	188,143	293,668
Cash and cash equivalents, end of period	210,569				116,370					210,569	116,370	188,143
Parent [Member]
Cash and Cash Equivalents, at Carrying Value	15,969				8,080					15,969	8,080	21,247
Other Assets	18,537				19,048					18,537	19,048
Total assets	353,652				330,569					353,652	330,569
Subordinated debentures	62,581				82,581					62,581	82,581
Notes payable	10,500				11,700					10,500	11,700
Accounts Payable and Accrued Liabilities	866				543					866	543
Stockholders' Equity Attributable to Parent	279,705				235,745					279,705	235,745
Liabilities and Equity	353,652				330,569					353,652	330,569
Cash Dividends Paid to Parent Company by Consolidated Subsidiaries										10,000	15,000	0
Other Income										256	527	624
Revenue, Net										10,256	15,527	624
Subordinated debentures										2,884	3,827	4,262
Interest Expense										396	64	0
Other Expenses										5,142	5,462	3,935
Operating Expenses										8,422	9,353	8,197
Income (Loss) from Continuing Operations Attributable to Parent										1,834	6,174	(7,573)
Income tax expense										3,394	3,739	2,568
Net income										5,228	9,913	(5,005)
Undistributed Earnings, Basic										27,876	18,383	30,428
Net income available to common shareholders										33,104	28,296	25,423
Share-based compensation										5,049	2,537	1,466
Income (Loss) from Equity Method Investments										(37,876)	(33,383)	(30,428)
Excess Tax Benefit (Tax Deficiency) from Share-based Compensation, Operating Activities										(222)	(66)	53
Other Operating Activities, Cash Flow Statement										2,004	2,064	1,207
Net Cash Provided by (Used in) Operating Activities										12,059	14,448	(2,279)
Payments to Acquire Businesses and Interest in Affiliates										0	0	(20,150)
Payments to Acquire Investments										(761)	(970)	(1,114)
Proceeds from Interest and Dividends Received										243	541	694
Net Cash Provided by (Used in) Investing Activities										(518)	(429)	(20,570)
Proceeds from notes payable										0	12,000	0
Repayments of notes payable										(1,200)	(300)	0
Debt issuance costs										0	(45)	0
Cash dividends paid on common stock										(3,947)	(3,757)	(3,577)
Excess tax benefit of share-based compensation										222	66	(53)
Payments for the repurchase of preferred stock										0	(35,000)	0
Cash dividends paid on preferred stock										0	(1,711)	(1,750)
Issuance of common stock										13	3	32,612
Proceeds from the issuance of equity instruments										2,266	1,558	1,468
Net Cash Provided by (Used in) Financing Activities										(3,652)	(27,186)	28,700
Cash and Cash Equivalents, Period Increase (Decrease)										7,889	(13,167)	5,851
Cash and cash equivalents, beginning of period				8,080				21,247	21,247	8,080	21,247	15,396
Cash and cash equivalents, end of period	15,969				8,080					15,969	8,080	21,247
Enterprise Bank and Trust [Member] | Parent [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	318,721				303,170					318,721	303,170
Enterprise Financial CDE LLC [Member] | Parent [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	$ 425				$ 271					$ 425	$ 271