Compensation Plans - Summary of Outstanding Equity Awards (Details)	Jun. 30, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock outstanding	1,200,557
Total restricted stock outstanding	1,305,053
Stock options outstanding	321,490	469,289
ARI [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total restricted stock outstanding	104,496
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Leadership grants	405,826
Amended And Restated 2003 Annual And Long -Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock outstanding	1,171,398
Amended And Restated 2003 Annual And Long -Term Incentive Plan | Annual grants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock outstanding	825,343
Amended And Restated 2003 Annual And Long -Term Incentive Plan | Sign-on grants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock outstanding	346,055
2010 Employment Inducement Award Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock outstanding	29,159