Basis of Presentation - Additional Information (Detail) (USD $)	3 Months Ended		12 Months Ended		3 Months Ended						1 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 Delaware [Member]	Mar. 31, 2013 Pennsylvania [Member]	Mar. 31, 2013 Virginia [Member]	Mar. 31, 2013 Nevada [Member]	Mar. 31, 2013 WSFS Bank [Member] Subsidiary	Mar. 31, 2013 Montchanin [Member] Subsidiary	Apr. 25, 2013 Subsequent Event [Member]	Mar. 31, 2013 Stock Incentive 2005 Plan [Member]	Mar. 31, 2013 Restricted Stock [Member]	Mar. 31, 2013 Performance Stock Awards [Member]	Mar. 31, 2012 Performance Stock Awards [Member]	Apr. 25, 2013 Non Statutory Stock Options [Member] Subsequent Event [Member] CEO [Member]	Apr. 25, 2013 Incentive Stock Option Awards [Member] Subsequent Event [Member] Executive [Member]	Mar. 31, 2013 Minimum [Member]	Mar. 31, 2013 Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of wholly-owned subsidiaries									2	1
Number of offices	51				42	7	1	1
Number of shares reserved for issuance under 2005 Plan	435,804	447,901	335,730	416,886								1,197,000
Shares available for future grants under 2005 Plan												49,175
Stock Options granted, vest in percentage per annum increments	25.00%		25.00%
Performance award vesting period	5 years										5 years		4 years					1 year	5 years
Total compensation cost to be recognized of non-vested stock options	$ 1,600,000															$ 3,700,000	$ 2,200,000
Expected weighted-average period	2 years 8 months 12 days										5 years
Restricted stock units and awards issued													11,357
Total amount of compensation cost of relating to non-vested restricted stock													1,900,000
Weighted-Average Remaining Contractual Life													2 years 3 months 18 days
Restricted stock granted	122,357	32,830											22,250
Pre-tax contributions achievement Period	Two year
Return on investment of cost of restricted stock	50.00%
Stock-based compensation expenses, pre-tax	946,000	711,000												69,000	103,000
Restricted stock vested, shares	5,563
Stock-based compensation expenses, after tax	804,000	545,000
Stock-based compensation expenses, per share	$ 0.09	$ 0.06
Stock option expense	$ 521,000
Stock options, granted	122,357	32,830														250,000	150,000
Stock options, exercise price	$ 44.19	$ 43.41	$ 42.14	$ 43.52							$ 49.52
Stock options, expiration period											7 years
Percentage of vesting stock after second year											40.00%
Percentage of vesting stock after second year, in each of the following three years											20.00%
Stock options vesting percentage, description											40% vesting after the second year and 20% vesting in each of the following three years