Stock-Based Compensation - Narrative (Details)	12 Months Ended
	Dec. 31, 2015 USD ($) employee $ / shares shares	Dec. 31, 2014 USD ($) employee $ / shares shares	Dec. 31, 2013 USD ($) employee $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of employees affected | employee	37	17	1
Net increase in share-based compensation	$ 3,400,000	$ 1,000,000
Stock-based compensation expense	7,204,000	4,712,000	$ 2,312,000
Stock-based compensation	$ 6,462,000	$ 4,712,000	$ 2,313,000
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Expected term (in years)	5 years	5 years	5 years
Expiration period	5 years
Stock-based compensation expense	$ 658,000	$ 117,000	$ 48,000
Weighted-average grant-date fair value	800,000	600,000	100,000
Intrinsic value of options exercised	0	4,900,000	800,000
Shares issued as a result of options exercised	$ 0	6,100,000	1,200,000
Stock appreciation rights
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Expected term (in years)	5 years
Stock-based compensation expense	$ 742,000	0	0
Aggregate weighted average grant-date fair value of share granted	$ 0
Exercise price (in usd per share) | $ / shares	$ 0.00
Stock appreciation rights | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 500,000
Exercise price (in usd per share) | $ / shares	$ 13.87
Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 2,909,000	2,612,000	1,681,000
Aggregate weighted average grant-date fair value of share granted	1,900,000	2,800,000	1,400,000
Fair value of shares vested	$ 2,900,000	$ 1,900,000	$ 700,000
Exercise price (in usd per share) | $ / shares	$ 17.51	$ 15.75	$ 10.73
Restricted stock awards | Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares accelerated, number (in shares) | shares	95,088	55,106	744
Stock-based compensation	$ 1,200,000	$ 1,000,000	$ 0
Restricted stock awards | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Restricted stock awards | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	5 years
Performance share units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	3 years	3 years	3 years
Service period	3 years
Net increase in share-based compensation	$ 2,100,000	$ 200,000
Stock-based compensation expense	2,895,000	1,983,000	$ 583,000
Aggregate weighted average grant-date fair value of share granted	$ 1,400,000	$ 2,200,000	$ 2,300,000
Exercise price (in usd per share) | $ / shares	$ 30.52	$ 0.00	$ 0.00
Other matters
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash received from share-based payment exercises	$ 0	$ 200,000	$ 400,000
2005 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for issuance (in shares) | shares	180,000
2005 Plan | Stock compensation plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares per employee (in shares) | shares	2,000
Shares reserved for issuance (in shares) | shares	100,000
2005 Plan | Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares per employee (in shares) | shares	10,000
Shares reserved for issuance (in shares) | shares	80,000
Vesting period	3 years
2007 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares per employee (in shares) | shares	400,000
Shares authorized for issuance (in shares) | shares	3,600,000
Maximum number of common shares to be received by participant, percent	200.00%
Maximum reduction in number of common shares to be received by participants, percent	0.00%
Percent of award based on performance of total stockholder return	75.00%
2007 Plan | Non-management Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares per employee (in shares) | shares	50,000
2010 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for issuance (in shares) | shares	600,000
401 (k) Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for issuance (in shares) | shares	600,000