Investment in Securities (Tables)

12 Months Ended

Dec. 31, 2014

Investment in Securities [Abstract]

Schedule of Available-for-sale Securities

The amortized cost, gross unrealized gains, gross unrealized losses and fair value of debt and equity securities are summarized as follows:

	December 31, 2014
			Gross		Gross
	Amortized		Unrealized		Unrealized
(In thousands)	Cost		Gains		Losses		Fair Value
State and political subdivisions	$	338,469	$	14,120	$	198	$	352,391
Certificates of deposit		3,750		—		—		3,750
Total	$	342,219	$	14,120	$	198	$	356,141
	December 31, 2013
			Gross		Gross
	Amortized		Unrealized		Unrealized
(In thousands)	Cost		Gains		Losses		Fair Value
State and political subdivisions	$	308,403	$	8,537	$	2,923	$	314,017
Certificates of deposit		3,750		—		—		3,750
Total	$	312,153	$	8,537	$	2,923	$	317,767

Schedule of Fair Value of Securities with Unrealized Losses

The fair values of securities with unrealized losses are as follows:

	December 31, 2014
	Less than 12 months				12 months or more				Total
	Estimated		Unrealized		Estimated		Unrealized		Estimated		Unrealized
(In thousands)	Fair Value		Losses		Fair Value		Losses		Fair value		Losses
State and political subdivisions	$	8,700	$	15	$	13,833	$	183	$	22,533	$	198
Certificates of deposit		—		—		—		—		—		—
Total	$	8,700	$	15	$	13,833	$	183	$	22,533	$	198
	December 31, 2013
	Less than 12 months				12 months or more				Total
	Estimated		Unrealized		Estimated		Unrealized		Estimated		Unrealized
(In thousands)	Fair Value		Losses		Fair Value		Losses		Fair value		Losses
State and political subdivisions	$	101,792	$	2,661	$	3,554	$	262	$	105,346	$	2,923
Certificates of deposit		—		—		—		—		—		—
Total	$	101,792	$	2,661	$	3,554	$	262	$	105,346	$	2,923

Schedule of Amortized Cost and Fair Value

	December 31, 2014
(In thousands)	Amortized Cost		Fair Value
Due in 1 year or less	$	27,929	$	28,213
Due after 1 year through 5 years		80,542		84,500
Due after 5 years through 10 years		144,350		150,428
Due after 10 years		89,398		93,000
No stated maturity		—		—
Total	$	342,219	$	356,141