Stock-Based Compensation Plans (Narrative) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended							12 Months Ended									1 Months Ended		12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010	Dec. 31, 2013 2004 Stock Plan [Member]	Dec. 31, 2012 2004 Stock Plan [Member]	Dec. 31, 2011 2004 Stock Plan [Member]	Dec. 31, 2013 2004 Director Plan [Member]	Dec. 31, 2012 2004 Director Plan [Member]	Dec. 31, 2011 2004 Director Plan [Member]	Dec. 31, 2013 Restricted Stock [Member] 2004 Stock Plan [Member]	Dec. 31, 2012 Restricted Stock [Member] 2004 Stock Plan [Member]	Dec. 31, 2011 Restricted Stock [Member] 2004 Stock Plan [Member]	Apr. 30, 2013 Non Employee Directors [Member] 2004 Director Plan [Member]	Apr. 30, 2011 Non Employee Directors [Member] 2004 Director Plan [Member]	Dec. 31, 2013 Non Employee Directors [Member] 2004 Director Plan [Member]	Dec. 31, 2012 Non Employee Directors [Member] 2004 Director Plan [Member]	Dec. 31, 2011 Non Employee Directors [Member] 2004 Director Plan [Member]	Dec. 31, 2013 Non Employee Directors [Member] Initial Grants [Member] 2004 Director Plan [Member]	Dec. 31, 2013 Non Employee Directors [Member] Annual Grants [Member] 2004 Director Plan [Member]	Dec. 31, 2013 Non Employee Directors [Member] Interim Grants [Member] 2004 Director Plan [Member]	Dec. 31, 2013 Minimum [Member]	Dec. 31, 2013 Maximum [Member]	Dec. 31, 2013 Maximum [Member] 2004 Stock Plan [Member]	Dec. 31, 2008 Maximum [Member] 2004 Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options outstanding, number	0		0		1,076		1,554
Common stock reserved for issuance																											6,000	4,000
Stock-based compensation expense, Shares														1,046	540	384			12	11	16
Estimated value associated with awards granted								$ 67,942	$ 20,458	$ 8,007
Share based compensation expense								12,958	4,818	2,337	600	300	300
Share-based compensation award vesting period																									3 years	5 years
Common stock available for future grants	1,445	[1]	1,667	[1]	2,217	[1]		1,295			150								600
Common stock issued upon reaching milestones																						1	3	3
Limit on value of award shares to directors																	100	50
Payment for per share granted								$ 1.00
Percentage of fair market value of common stock at grant date	10.00%
Number of stock options exercised	0		1,056		452
Aggregate intrinsic value of stock option exercised			$ 39,165		$ 5,298

[1] Assumes the issuance of options permitted by the 2004 Incentive Stock Plan.