Investments (Gross Unrealized Losses and Fair Values of Securities) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2012
Schedule of Investments [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than twelve months, fair value	$ 42,706	$ 182,255
Available-for-sale securities, continuous unrealized loss position, less than 12 months, unrealized losses	260	8,361
Available-for-sale securities, continuous unrealized loss position, twelve months or longer, fair value	75,263	80,051
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses	15,268	25,488
Held-to-maturity securities, continuous unrealized loss position, less than twelve months, fair value	79,416
Held-to-maturity securities, continuous unrealized loss position, less than 12 months, unrealized loss	555
Held-to-maturity securities, continuous unrealized loss position, twelve months or longer, fair value	2,476
Held-to-maturity securities, continuous unrealized loss position, 12 months or longer, unrealized loss	249
U.S. Treasury [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than twelve months, fair value	10,078
Available-for-sale securities, continuous unrealized loss position, less than 12 months, unrealized losses	17
Available-for-sale securities, continuous unrealized loss position, twelve months or longer, fair value	0
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses	0
U.S. Government Agencies [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than twelve months, fair value	0	62,962
Available-for-sale securities, continuous unrealized loss position, less than 12 months, unrealized losses	0	3,154
Available-for-sale securities, continuous unrealized loss position, twelve months or longer, fair value	18,664	13,996
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses	411	2,067
Held-to-maturity securities, continuous unrealized loss position, less than twelve months, fair value	14,945
Held-to-maturity securities, continuous unrealized loss position, less than 12 months, unrealized loss	109
Held-to-maturity securities, continuous unrealized loss position, twelve months or longer, fair value	0
Held-to-maturity securities, continuous unrealized loss position, 12 months or longer, unrealized loss	0
Residential Mortgage-backed Agencies [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than twelve months, fair value	9,974	60,781
Available-for-sale securities, continuous unrealized loss position, less than 12 months, unrealized losses	1	1,801
Available-for-sale securities, continuous unrealized loss position, twelve months or longer, fair value	23,786	46,570
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses	725	3,022
Held-to-maturity securities, continuous unrealized loss position, less than twelve months, fair value	47,209
Held-to-maturity securities, continuous unrealized loss position, less than 12 months, unrealized loss	263
Held-to-maturity securities, continuous unrealized loss position, twelve months or longer, fair value	0
Held-to-maturity securities, continuous unrealized loss position, 12 months or longer, unrealized loss	0
Commercial Mortgage-backed Agencies [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than twelve months, fair value	20,480	21,889
Available-for-sale securities, continuous unrealized loss position, less than 12 months, unrealized losses	235	1,134
Available-for-sale securities, continuous unrealized loss position, twelve months or longer, fair value	969	0
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses	15	0
Held-to-maturity securities, continuous unrealized loss position, less than twelve months, fair value	9,660
Held-to-maturity securities, continuous unrealized loss position, less than 12 months, unrealized loss	73
Held-to-maturity securities, continuous unrealized loss position, twelve months or longer, fair value	0
Held-to-maturity securities, continuous unrealized loss position, 12 months or longer, unrealized loss	0
Collateralized Mortgage Obligations [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than twelve months, fair value	2,174	21,201
Available-for-sale securities, continuous unrealized loss position, less than 12 months, unrealized losses	7	1,149
Available-for-sale securities, continuous unrealized loss position, twelve months or longer, fair value	0	3,051
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses	0	13
Held-to-maturity securities, continuous unrealized loss position, less than twelve months, fair value	7,602
Held-to-maturity securities, continuous unrealized loss position, less than 12 months, unrealized loss	110
Held-to-maturity securities, continuous unrealized loss position, twelve months or longer, fair value	0
Held-to-maturity securities, continuous unrealized loss position, 12 months or longer, unrealized loss	0
Obligations of States and Political Subdivisions [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than twelve months, fair value	0	15,422
Available-for-sale securities, continuous unrealized loss position, less than 12 months, unrealized losses	0	1,123
Available-for-sale securities, continuous unrealized loss position, twelve months or longer, fair value	12,450	0
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses	234	0
Held-to-maturity securities, continuous unrealized loss position, less than twelve months, fair value	0	0
Held-to-maturity securities, continuous unrealized loss position, less than 12 months, unrealized loss	0	0
Held-to-maturity securities, continuous unrealized loss position, twelve months or longer, fair value	2,476	2,301
Held-to-maturity securities, continuous unrealized loss position, 12 months or longer, unrealized loss	249	559
Collateralized Debt Obligations [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than twelve months, fair value	0	0
Available-for-sale securities, continuous unrealized loss position, less than 12 months, unrealized losses	0	0
Available-for-sale securities, continuous unrealized loss position, twelve months or longer, fair value	19,394	16,434
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses	$ 13,883	$ 20,386