Business Combination (Details) (USD $)	3 Months Ended				3 Months Ended		1 Months Ended	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Dec. 31, 2011	Mar. 31, 2013 American Heritage Holdings [Member]	Feb. 28, 2013 American Heritage Holdings [Member]	Mar. 31, 2012 First Independent Bank [Member]	Mar. 31, 2013 First Independent Bank [Member]	Mar. 31, 2012 First Independent Bank [Member]	Feb. 29, 2012 First Independent Bank [Member]	Feb. 28, 2013 Evidence of Credit Deterioration [Member]	Feb. 29, 2012 Evidence of Credit Deterioration [Member]	Feb. 28, 2013 No Evidence of credit deterioration [Member]	Feb. 29, 2012 No Evidence of credit deterioration [Member]	Mar. 31, 2013 Maximum [Member] First Independent Bank [Member]	Mar. 31, 2013 Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]
Business Acquisition, Cost of Acquired Entity, Purchase Price [Abstract]
Business Combination, Consideration Transferred						$ 6,500,000
Business Combination, Consideration Transferred, Other						2,200,000
Cash paid						8,749,000				28,900,000
Bargain purchase gain	7,544,000	0			7,544,000
Net purchase price										40,600,000
Contingent consideration fair value		11,779,000	15,442,000	0						11,700,000						9,190,000	15,442,000
Contingent consideration maximum amount															17,000,000
stsa_CashPaidContingentConsideration	(6,838,000)	0						(6,838,000)
Business Acquisition, Purchase Price Allocation, Noncurrent Assets [Abstract]
Cash and cash equivalents						15,626,000				150,045,000
Investments and MBS						1,030,000				187,465,000
Loans receivable, net						97,262,000				349,990,000
Goodwill	22,577,000	21,730,000	22,577,000	0						22,577,000
Core deposit intangible						453,000				11,974,000
Fixed assets										4,038,000
Other assets						27,197,000				10,886,000
Total assets acquired						141,568,000				736,975,000
Deposits						118,221,000				695,919,000
Other Liabilties						7,054,000				409,000
Total liabilities assumed						125,275,000				696,328,000
Net assets acquired						16,293,000				40,647,000
Contractual cash flows											16,100,000	24,408,000
Expected cash flows											13,600,000	17,188,000
Present value of expected cash flows											(11,900,000)	(15,265,000)
Loan Principal Guaranteed By Government Agencies											9,800,000
Unpaid principal balance and contractual interest													83,300,000	403,800,000
Cash flows not expected to be collected													3,900,000	12,700,000
Discount on acquired loans													4,500,000	21,800,000
Business Acquisition, Pro Forma Information [Abstract]
Net interest income							3,241,000		80,834,000
Noninterest income							503,000		32,592,000
Net income							$ 2,107,000		$ 17,505,000
Earnigns per share - basic							$ 0.03		$ 0.28
Earnings per share - diluted							$ 0.03		$ 0.28