Summary of Significant Accounting Policies (Net Income Per Share) (Details) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Weighted Average Number of Shares Outstanding, Basic	71,543	70,374	69,283
Weighted Average Number of Shares Outstanding, Diluted	72,703	72,236	70,731
Employee Stock Options [Member]
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	286	783	510
Restricted Stock Units (RSUs) [Member]
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	874	1,079	938