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
Earnings Per Share [Abstract]
Net income	$ 16,828	$ 13,139	$ 32,072	$ 27,301
Weighted average shares outstanding - basic and diluted (in shares)	5,110,369	5,108,745	5,110,045	5,108,383
Net income per common share- basic and diluted (in dollars per share)	$ 3.29	$ 2.57	$ 6.28	$ 5.34