Condensed Consolidated Statement of Changes in Stockholders' Equity (Unaudited) (USD $) In Thousands	Common Stock [Member]	Preferred Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balance at Dec. 31, 2013	$ 641	$ 72,397	$ 404,555		$ 3,073	$ 480,666
Net income				94,215		94,215
Stock issuance, net	266		186,397			186,663
Dividends declared				(73,770)		(73,770)
Reclassification adjustment for net gain included in net income					(4,884)	(4,884)
Increase in net unrealized gain on available for sale securities					25,636	25,636
Decrease in fair value of derivative instruments utilized for cash flow hedges					(149)	(149)
Balance at Sep. 30, 2014	$ 907	$ 72,397	$ 590,952	$ 20,445	$ 23,676	$ 708,377