Stock-Based Compensation (Stock Option Activity) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Shares
Outstanding at beginning of year	2,550,046	3,220,110	2,755,672
Option rounding due to reverse stock split on May 16, 2014	0	841	0
Options granted	0	0	857,607
Options exercised	(338,808)	(178,176)	(65,109)
Options forfeited	(12,825)	(30,146)	(52,011)
Options expired	(456,438)	(462,583)	(276,049)
Options outstanding at end of year	1,741,975	2,550,046	3,220,110
Options exercisable at end of year	1,504,783	1,870,516	1,999,195
Weighted-Average Exercise Price
Outstanding at beginning of year	$ 45.11	$ 49.00	$ 58.80
Option rounding due to reverse stock split on May 16, 2014	0.00	49.00	0.00
Options granted	0.00	0.00	17.64
Options exercised	16.72	17.14	17.29
Options forfeited	17.17	15.79	16.45
Options expired	94.56	84.88	62.86
Options outstanding at end of year	37.88	45.11	49.00
Options exercisable at end of year	$ 41.08	$ 55.40	$ 68.74