Borrowed Funds (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Summary of borrowed funds
Due within 12 months, Weighted average rate	2.70%	2.69%
Due beyond 12 months but within 2 years, Weighted average rate	2.83%	2.88%
Due beyond 2 years but within 3 years, Weighted average rate	1.79%	3.13%
Due beyond 3 years but within 4 years, Weighted average rate	1.36%	2.15%
Due beyond 4 years but within 5 years, Weighted average rate	0.93%	1.03%
Due beyond 5 years, Weighted average rate	3.61%	3.61%
Due within 12 months	$ 112,582	$ 100,147
Due beyond 12 months but within 2 years	59,202	71,392
Due beyond 2 years but within 3 years	38,071	15,873
Due beyond 3 years but within 4 years	32,234	8,013
Due beyond 4 years but within 5 years	5,179	7,807
Due beyond 5 years	10,000	10,000
Total	257,268	213,232
Repurchase agreements [Member]
Summary of borrowed funds
Due within 12 months, Weighted average rate	2.82%	2.99%
Due beyond 12 months but within 2 years, Weighted average rate	3.28%	3.07%
Due beyond 2 years but within 3 years, Weighted average rate	4.12%	4.12%
Due beyond 4 years but within 5 years, Weighted average rate	4.28%	4.28%
Due beyond 5 years, Weighted average rate	4.49%	4.49%
Due within 12 months	78,000	148,000
Due beyond 12 months but within 2 years	20,000	40,000
Due beyond 2 years but within 3 years	10,000	10,000
Due beyond 4 years but within 5 years	25,000	25,000
Due beyond 5 years	45,000	45,000
Total	178,000	268,000
ESOP borrowings [Member]
Summary of borrowed funds
Due within 12 months, Weighted average rate	4.68%	4.68%
Due beyond 12 months but within 2 years, Weighted average rate	4.68%	4.68%
Due beyond 2 years but within 3 years, Weighted average rate	4.68%	4.68%
Due beyond 3 years but within 4 years, Weighted average rate		4.68%
Due within 12 months, Amount	1,000	1,000
Due beyond 12 months but within 2 years	1,000	1,000
Due beyond 2 years but within 3 years	1,000	1,000
Due beyond 3 years but within 4 years		250
Total	3,000	3,250
Corporate borrowings [Member]
Summary of borrowed funds
Due within 12 months, Weighted average rate	3.75%
Due beyond 12 months but within 2 years, Weighted average rate	3.75%
Due beyond 2 years but within 3 years, Weighted average rate	3.75%
Due beyond 3 years but within 4 years, Weighted average rate	3.75%
Due beyond 4 years but within 5 years, Weighted average rate	3.75%
Due within 12 months, Amount	1,000
Due beyond 12 months but within 2 years	1,000
Due beyond 2 years but within 3 years	1,000
Due beyond 3 years but within 4 years	1,000
Due beyond 4 years but within 5 years	5,954
Total	9,954
Borrowings for joint ventures [Member]
Summary of borrowed funds
Due beyond 2 years but within 3 years, Weighted average rate	3.75%	3.75%
Due beyond 2 years but within 3 years	9	74
Junior subordinated notes [Member]
Summary of borrowed funds
Due beyond 5 years, Weighted average rate	2.11%	2.41%
Due beyond 5 years	$ 36,083	$ 46,393