Additional Information to Stock Options Exercised (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Schedule Of Stock Options [Line Items]
Income tax benefit	$ 1,627	$ 1,724	$ 2,684	$ 2,520
Stock Options
Schedule Of Stock Options [Line Items]
Intrinsic value			6,691	9,246
Exercise proceeds			9,075	11,956
Income tax benefit			$ 1,951	$ 2,711