Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Computation of Basic and Diluted Shares
Net income	$ 8,822	$ 4,879	$ 14,581	$ 7,712
Weighted average shares outstanding - basic	7,523,347	7,349,868	7,499,016	7,318,688
Dilutive potential shares from unvested restricted shares	215,803	145,655	221,409	173,704
Weighted average shares outstanding - diluted	7,739,150	7,495,523	7,720,425	7,492,392
Earnings per share:
Basic	$ 1.17	$ 0.66	$ 1.94	$ 1.05
Diluted	$ 1.14	$ 0.65	$ 1.89	$ 1.03