Shareholders' Equity and Stock Compensation (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 31, 2016	Feb. 29, 2016	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Shareholders Equity and Share-Based Payments [Line Items]
Stock repurchased during period (in shares)		235,000
Stock repurchased during period		$ 3,500			$ 9,374		$ 14,589
Compensation cost			$ 1,600	$ 4,400	4,700	$ 7,600
Total income tax benefit recognized related to stock-based compensation			638	1,600	1,800	2,800
Total intrinsic value of options exercised			46	320	178	465
Cash received from exercise of stock options			142	621	777	760
Income tax benefits received			3,400	1,700	5,300	4,400
Net tax benefit from stock options exercised						529
Employee Stock Option
Shareholders Equity and Share-Based Payments [Line Items]
Cash received from exercise of stock options			34	105	67	194
Total unrecognized compensation cost related to nonvested stock awards			73		$ 73
Expected recognized over a weighted-average period, years					1 year 3 months 4 days
Restricted Stock
Shareholders Equity and Share-Based Payments [Line Items]
Total fair value of restricted stock shares/units vested and released			6,900	1,700	$ 11,300	6,800
Total unrecognized compensation cost related to nonvested stock awards			10,600		$ 10,600
Expected recognized over a weighted-average period, years					1 year 10 months 21 days
Restricted Stock Units (RSUs)
Shareholders Equity and Share-Based Payments [Line Items]
Total fair value of restricted stock shares/units vested and released			1,800	$ 2,500	$ 2,100	$ 3,900
Total unrecognized compensation cost related to nonvested stock awards			$ 2,500		$ 2,500
Expected recognized over a weighted-average period, years					1 year 5 months 1 day
Subsequent Event
Shareholders Equity and Share-Based Payments [Line Items]
Stock repurchased during period (in shares)	325,000