Stock-Based Compensation (Activity in the Stock Plan) (Details) - shares	1 Months Ended	9 Months Ended	105 Months Ended	153 Months Ended
	May 31, 2014	Sep. 30, 2017	Sep. 30, 2017	Sep. 30, 2017
Employee Stock Award Plan-2008
Authorized Shares Available for Future Award Grants
Beginning balance (in shares)		1,248,651	1,900,000
Additional shares authorized (in shares)	1,500,000	0	1,500,000
Number of awards granted (in shares)		(255,040)	(2,867,606)
Number of awards forfeited or expired (in shares)		3,228	464,445
Ending balance (in shares)		996,839	996,839	996,839
Employee Stock Award Plan-2008 | Options Awards
Authorized Shares Available for Future Award Grants
Number of option awards exercised (in shares)		101,189	1,050,257
Employee Stock Award Plan-2008 | Unrestricted Stock Awards
Authorized Shares Available for Future Award Grants
Number of awards granted (in shares)		(1,145)	(8,470)
Employee Stock Award Plan-2008 | Restricted Stock Awards
Authorized Shares Available for Future Award Grants
Number of restricted stock awards vested (in shares)		0	36,970
Director Plan - 2005
Authorized Shares Available for Future Award Grants
Beginning balance (in shares)		74,771		300,000
Number of awards granted (in shares)		(12,958)		(262,190)
Number of awards forfeited or expired (in shares)		0		24,003
Ending balance (in shares)		61,813	61,813	61,813
Director Plan - 2005 | Options Awards
Authorized Shares Available for Future Award Grants
Number of option awards exercised (in shares)		6,727		59,200
Number of restricted stock awards vested (in shares)		22,716		54,272