Share-based Compensation (Nonvested Options) (Details) (Nonvested Option Shares, USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Nonvested Option Shares
Nonvested Awards, Number of Shares [Roll Forward]
Nonvested awards, Shares, beginning balance	112,500	135,000	180,005
Nonvested options, Granted	0	45,000	45,000
Nonvested options, Vested	(45,000)	(67,500)	(90,005)
Nonvested options, Canceled	0	0	0
Nonvested awards, Shares, ending balance	67,500	112,500	135,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Exercise Price [Roll Forward]
Nonvested options, Weighted Average Exercise Price, beginning balance (in dollars per share)	$ 17.32	$ 18.80	$ 17.17
Nonvested options, Granted, Weighted Average Exercise Price (in dollars per share)	$ 0.00	$ 14.89	$ 16.94
Nonvested options, Vested, Weighted Average Exercise Price (in dollars per share)	$ 18.53	$ 18.66	$ 14.60
Nonvested options, Canceled, Weighted Average Exercise Price (in dollars per share)	$ 0.00	$ 0.00	$ 0.00
Nonvested options, Weighted Average Exercise Price, ending balance (in dollars per share)	$ 16.52	$ 17.32	$ 18.80