Equity-Based Compensation - Restricted Stock Awards with Performance Conditions Additional Information (Details) $ / shares in Units, $ in Thousands			2 Months Ended	12 Months Ended
	Feb. 27, 2015 $ / shares	Feb. 28, 2014 $ / shares	Mar. 15, 2016 shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) employee $ / shares shares	Dec. 31, 2013 USD ($) $ / shares shares	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accelerated compensation cost | $						$ 1,500
Share-based compensation expense | $				$ 10,100	$ 9,400	6,200
Unrecognized equity-based compensation | $				$ 28,909	$ 40,215	$ 10,420
Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, granted				581,672	3,239,948	183,190
Weighted average grant date fair value, vested (in usd per share) | $ / shares				$ 18.2	$ 11.76	$ 10.02
Number of Shares, Vested				785,820	299,703	202,689
Number of shares forfeited in period				70,299	370,041	12,893
Unrecognized equity-based compensation | $				$ 18,946	$ 37,780	$ 7,526
2011 Executive Performance Based Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accelerated compensation cost reversal | $						$ 1,500
2013 Performance based plan | Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, granted						130,440
Share-based payment award distributed percentage						50.00%
Weighted average grant date fair value, vested (in usd per share) | $ / shares						$ 13.09
Performance Metrics of GovDelivery | Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, granted					244,506
Number of employees granted shares in period | employee					2
Number of Shares, Vested				56,587
Number of shares forfeited in period				43,660
Performance Metrics of GovDelivery | Restricted stock | Vesting in first quarter of 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, granted					100,247
Performance Metrics of GovDelivery | Restricted stock | Vesting in second quarter of 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, granted					144,259
2014 Performance based plan | Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, granted					158,942
Weighted average grant date fair value, vested (in usd per share) | $ / shares		$ 20.33
2015 Performance based plan | Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, granted				316,715
Weighted average grant date fair value, vested (in usd per share) | $ / shares	$ 16.76
Number of shares expected to vest				175,248
Share-based compensation expense | $				$ 4,100	$ 4,900	$ (1,100)
Unrecognized equity-based compensation | $				$ 100
Chief Executive Officer And President | Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Tax benefit from compensation expense | $						$ 400	$ 900	$ 200
Chief Executive Officer And President | Awards With Market Conditions | Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, granted								366,666
Executive Officer | Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, granted				20,000
Executive Officer | Performance based plan | Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, granted				42,341
Number of Shares, Vested				28,341
Number of shares forfeited in period				14,000
Condition one | 2013 Performance based plan | Restricted stock | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of financial targets to be achieved for participants to receive award						50.00%
Condition one | 2014 Performance based plan | Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of financial targets to be achieved for participants to receive award					100.00%
Condition one | 2015 Performance based plan | Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of financial targets to be achieved for participants to receive award				150.00%
Condition two | 2013 Performance based plan | Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of financial targets to be achieved for participants to receive award					200.00%
Condition two | 2013 Performance based plan | Restricted stock | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of financial targets to be achieved for participants to receive award						0.00%
Condition two | 2013 Performance based plan | Restricted stock | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of financial targets to be achieved for participants to receive award						50.00%
Condition two | 2014 Performance based plan | Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of financial targets to be achieved for participants to receive award					100.00%
Condition two | 2014 Performance based plan | Restricted stock | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of financial targets to be achieved for participants to receive award					0.00%
Condition two | 2014 Performance based plan | Restricted stock | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of financial targets to be achieved for participants to receive award					100.00%
Condition two | 2015 Performance based plan | Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of financial targets to be achieved for participants to receive award				150.00%
Condition two | 2015 Performance based plan | Restricted stock | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of financial targets to be achieved for participants to receive award				0.00%
Condition two | 2015 Performance based plan | Restricted stock | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of financial targets to be achieved for participants to receive award				150.00%
Subsequent event | Performance Metrics of GovDelivery | Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Vested			81,322
Number of shares forfeited in period			62,937