Share-Based Compensation , Narrative (Details) (USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended		1 Months Ended	9 Months Ended	1 Months Ended			9 Months Ended	1 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Jul. 24, 2014 Performance Shares [Member] 2009 Equity Plan [Member]	Sep. 30, 2014 Stock Options [Member] 2004 non-employee plan [Member]	Jul. 31, 2014 Restricted Stock [Member]	Jun. 30, 2014 Restricted Stock [Member]	Feb. 28, 2014 Restricted Stock [Member]	Sep. 30, 2014 Restricted Stock [Member]	Feb. 28, 2014 Restricted Stock [Member] 2004 non-employee plan [Member]	Jul. 24, 2014 Restricted Stock [Member] 2009 Equity Plan [Member]	Jul. 31, 2014 Restricted Stock [Member] 2009 Equity Plan [Member]	Jun. 30, 2014 Restricted Stock [Member] 2009 Equity Plan [Member]	Feb. 28, 2014 Restricted Stock [Member] 2009 Equity Plan [Member]	Jun. 30, 2013 Restricted Stock [Member] 2009 Equity Plan [Member]	Jul. 24, 2014 June 20, 2020 [Member] Performance Shares [Member] 2009 Equity Plan [Member]	Jul. 24, 2014 June 20, 2020 [Member] Restricted Stock [Member] 2009 Equity Plan [Member]	Jul. 31, 2014 July 2, 2017 [Member] Restricted Stock [Member] 2009 Equity Plan [Member]	Jul. 31, 2014 July 2, 2018 [Member] Restricted Stock [Member] 2009 Equity Plan [Member]	Jul. 31, 2014 July 2, 2019 [Member] Restricted Stock [Member] 2009 Equity Plan [Member]	Jul. 31, 2014 July 2, 2020 [Member] Restricted Stock [Member] 2009 Equity Plan [Member]	Jul. 31, 2014 July 2, 2021 [Member] 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)			175,000						14,000	75,000	3,500	20,250	16,000	250,000	100,000	150,000																50,000
Weighted average grant date fair value					$ 50.09	$ 49.84	$ 48.01
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights																	0.35	0.35	0.2	0.05	0.05	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	$ 126	$ 201
Vested restricted stock (in shares)								54,863