Incentive Stock Plans - Summary of Stock Option Activity (Details) - Stock Options $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) $ / shares shares
Options
Beginning balance (in shares) | shares	441,615
Forfeited (in shares) | shares	(1,435)
Exercised (in shares) | shares	0
Expired (in shares) | shares	(41,168)
Ending balance (in shares) | shares	399,012
Options vested and expected to vest (in shares) | shares	399,012
Options exercisable (in shares) | shares	374,702
Weighted Average Exercise Price
Beginning balance (in dollars per share) | $ / shares	$ 31.67
Forfeited (in dollars per share) | $ / shares	36.55
Exercised (in dollars per share) | $ / shares	0.00
Expired (in dollars per share) | $ / shares	29.81
Ending balance (in dollars per share) | $ / shares	31.85
Options vested and expected to vest (in dollars per share) | $ / shares	31.85
Options exercisable (in dollars per share) | $ / shares	$ 31.53
Additional Disclosures
Weighted Average Remaining Contractual Term, Outstanding	4 years 2 months 12 days
Weighted Average Remaining Contractual Term, Options vested and expected to vest	4 years 2 months 12 days
Weighted Average Remaining Contractual Term, Options exercisable	4 years
Aggregate Intrinsic Value, Outstanding | $	$ 0
Aggregate Intrinsic Value, Options vested and expected to vest | $	0
Aggregate Intrinsic Value, Options exercisable | $	$ 0