Income Taxes (Unrecognized Tax Benefits) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Summary of activities related to unrecognized tax benefits
Balance at the beginning of the period	$ 24,135,000	$ 25,446,000
Additions to tax positions related to the current year	0	0
Additions to tax positions related to prior years	222,000	248,000
Subtractions to tax positions related to prior years	0	(677,000)
Subtractions to tax positions related to settlements	0	0
Subtractions to tax positions as a result of the lapse of the statute of limitations	(3,407,000)	(882,000)
Balance at the end of the period	20,950,000	24,135,000
Unrecognized tax benefits that, if recognized, would reduce annual effective tax rate	19,300,000	$ 22,500,000
Unrecognized tax benefits, interest accrued	300,000
Unrecognized tax benefits, penalties accrued	0
Expected decrease in unrecognized tax benefits during next fiscal year	$ (4,300,000)