Share-Based Compensation , Narrative (Details) (USD $) In Thousands, except Share data, unless otherwise specified	6 Months Ended			1 Months Ended		6 Months Ended	1 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 Stock Options [Member] 2004 non-employee plan [Member]	Jun. 30, 2014 Restricted Stock [Member]	Feb. 28, 2014 Restricted Stock [Member]	Jun. 30, 2014 Restricted Stock [Member]	Feb. 28, 2014 Restricted Stock [Member] 2004 non-employee plan [Member]	Jun. 30, 2014 Restricted Stock [Member] 2009 Equity Plan [Member]	Feb. 28, 2014 Restricted Stock [Member] 2009 Equity Plan [Member]	Jun. 30, 2014 June 30, 2017 [Member] Restricted Stock [Member] 2009 Equity Plan [Member]	Jun. 30, 2014 June 30, 2018 [Member] Restricted Stock [Member] 2009 Equity Plan [Member]	Jun. 30, 2014 June 30, 2019 [Member] Restricted Stock [Member] 2009 Equity Plan [Member]	Jun. 30, 2014 June 30, 2020 [Member] Restricted Stock [Member] 2009 Equity Plan [Member]	Jun. 30, 2014 June 30, 2021 [Member] Restricted Stock [Member] 2009 Equity Plan [Member]	Feb. 28, 2014 February 12, 2018 [Member] Restricted Stock [Member] 2009 Equity Plan [Member]	Feb. 28, 2014 February 12, 2019 [Member] Restricted Stock [Member] 2009 Equity Plan [Member]	Feb. 28, 2014 February 12, 2020 [Member] Restricted Stock [Member] 2009 Equity Plan [Member]	Feb. 28, 2014 February 12, 2021 [Member] Restricted Stock [Member] 2009 Equity Plan [Member]	Feb. 28, 2014 February 12, 2022 [Member] Restricted Stock [Member] 2009 Equity Plan [Member]	Jun. 30, 2014 Executive Officer [Member] Restricted Stock [Member] 2009 Equity Plan [Member]	Jun. 30, 2014 Executive Officer [Member] June 30, 2018 [Member] Restricted Stock [Member] 2009 Equity Plan [Member]	Jun. 30, 2014 Executive Officer [Member] June 30, 2019 [Member] Restricted Stock [Member] 2009 Equity Plan [Member]	Jun. 30, 2014 Executive Officer [Member] June 30, 2020 [Member] Restricted Stock [Member] 2009 Equity Plan [Member]	Jun. 30, 2014 Executive Officer [Member] June 30, 2021 [Member] Restricted Stock [Member] 2009 Equity Plan [Member]	Jun. 30, 2014 Executive Officer [Member] June 30, 2022 [Member] Restricted Stock [Member] 2009 Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, shares (in shares)							14,000	20,250	16,000											50,000
Weighted average grant date fair value				$ 49.84	$ 48.01
Award vesting rights										0.35	0.35	0.2	0.05	0.05	0.2	0.3	0.35	0.1	0.05		0.2	0.3	0.35	0.1	0.05
Exercises in period			4,904
Proceeds from stock option exercise	$ 127	$ 149
Vested restricted stock (in shares)						18,045